Tight Approximation Algorithms for Scheduling with Fixed Jobs and Non-Availability

We study two closely related problems in non-preemptive scheduling of sequential jobs on identical parallel machines. In these two settings there are either fixed jobs or non-availability intervals during which the machines are not available; in both cases, the objective is to minimize the makespan. Both formulations have different applications, e.g. in turnaround scheduling or overlay computing. For both problems we contribute approximation algorithms with an improved ratio of $3/2+\epsilon$, respectively, which we refine to approximation algorithms with ratio $3/2$. For scheduling with fixed jobs, a lower bound of $3/2$ on the approximation ratio has been obtained by Scharbrodt, Steger & Weisser: for scheduling with non-availability we provide the same lower bound. In total, our approximation ratio for both problems is tight via suitable inapproximability results. We use dual approximation, creation of a gap structure and job configurations, and a PTAS for the multiple subset sum problem. However, the main feature of our algorithms is a new technique for the assignment of large jobs via flexible rounding. Our new technique is based on an interesting cyclic shifting argument in combination with a network flow model for the assignment of jobs to large gaps

Heuristic Approaches to Minimize Tour Duration for the TSP with Multiple Time Windows

We present heuristics to handle practical travelling salesman problems with multiple time windows per node, where the optimization goal is minimal tour duration, which is the time spent outside the depot node. We propose a dynamic programming approach which combines state labels by encoding intervals to handle the larger state space needed for this objective function. Our implementation is able to solve many practical instances in real-time and is used for heuristic search of near-optimal solutions for hard instances. In addition, we outline a hybrid genetic algorithm we implemented to cope with hard or unknown instances. Experimental evaluation proves the efficiency and suitability for practical use of our algorithms and even leads to improved upper bounds for yet unsolved instances from the literature

Tight Approximation Algorithms for Scheduling with Fixed Jobs and Non-Availability

We study two closely related problems in non-preemptive scheduling of jobs on identical parallel machines. In these two settings there are either fixed jobs or non-availability intervals during which the machines are not available; in both cases, the objective is to minimize the makespan. Both formulations have different applications, e.g. in turnaround scheduling or overlay computing. For both problems we contribute approximation algorithms with an improved ratio of 3/2. For scheduling with fixed jobs, a lower bound of 3/2 on the approximation ratio has been obtained by Scharbrodt, Steger & Weisser; for scheduling with non-availability we provide the same lower bound. We use dual approximation, creation of a gap structure and a PTAS for the multiple subset sum problem, combined with a post- processing step to assign large job

Взаимосвязь удельного показателя поглощения нефтей, природных битумов и их компонентов в видимой области спектра с параметрами их состава

Актуальность работы обусловлена необходимостью экспрессной оценки группового состава нефтей, их некоторых физико-химических и технологических свойств, в том числе для контроля над разработкой нефтяных месторождений. Опубликованные в литературе данные свидетельствуют, что для такой оценки используется удельный показатель поглощения их растворов при фиксированных длинах волн в различных областях спектра поглощения или площадь под кривой поглощения во всей области спектра поглощения. Нарушение линейной зависимости оптической плотности от концентрации в спектрах поглощения растворов нефтей и нефтяных фракций дает возможность изучать процессы образования и разрушения ассоциатов в нефтяных системах. В то же время в литературе практически отсутствуют попытки поиска взаимосвязи удельного показателя поглощения с параметрами, характеризующими наличие и относительное содержание различных структурных фрагментов в нефтях и нефтяных фракциях. Цель работы: выявление возможных корреляций между значением удельного показателя поглощения в видимой области спектра и параметрами, характеризующими наличие и относительное содержание различных структурных фрагментов в нефтях и нефтяных фракциях. Методы исследования: спектрофотометрия в видимой области спектра поглощения, методы ИК- и ЯМР 1Н-спектрометрии, корреляционный анализ. Результаты. Определены различные спектральные характеристики в видимой области спектра поглощения (удельный показатель поглощения при длине волны 500 нм, коэффициент цветности - E4/E6) нефтей, природных битумов и фракций, полученных при их экстракционно-хроматографическом разделении (масла, смолы, асфальтены). Выявлена взаимосвязь удельного показателя поглощения растворов изученных образцов при длине волны 500 нм (К500) с характеристиками изученных образцов, полученными методами ИК- и ЯМР 1Н-спектрометрии, отражающими относительное содержание ароматических и алифатических структурных фрагментов в их составе. Величина достоверности аппроксимации (R2) имеет наиболее высокие значения (от 0,790 до 0,892) только в случае функциональной связи K500 с параметрами, отражающими содержание ароматических структурных фрагментов для всей совокупности изученных образцов и для совокупности изученных нефтей и природных битумов. Для отдельных фракций эта взаимосвязь отсутствует.The relevance of the discussed issue is caused by the necessity of an express assessment of the component compositions of oils, some of their physicochemical and technological properties, including control over development of oil deposits. The published data indicate that for such assessment the specific absorption factor of their solutions at fixed wavelengths in different regions of absorption spectrum or the area under the curve of absorption in all regions of the absorption spectrum are used. Violation of linear dependence of optical density on concentration in the absorption spectra of oil and oil fraction solutions enables to study the processes of formation and destruction of associates in oil systems. At the same time there are practically no attempts in literature to search for correlation between the specific absorption factor and the parameters characterizing the occurrence and relative content of various structural fragments in oils and oil fraction. The main aim of the study is to reveal possible correlations between the values of specific absorption factor in visible spectral region and the parameters characterizing the occurrence and relative content of various structural fragments in oils and oil fraction. The methods used in the study: spectrophotometry in visible absorption spectrum, IR- and 1H NMR spectroscopy methods, correlation analysis. The results. The authors have determined different spectral characteristics in visible region of the absorption spectrum (specific absorption factor at a wavelength of 500 nm, chromaticity coefficient is E4/E6) of oils, natural bitumen and fraction obtained during their extraction-chromatographic separation (oily components, resins and asphaltenes). The correlation between the specific absorption factor of the investigated samples solutions at a wavelength of 500 nm (K500) and the characteristics of the investigated samples obtained by the methods of IR- and 1H NMR spectroscopy, reflecting the relative content of aromatic and aliphatic structural fragments in their compositions, was determined. The approximation credibility (R2) magnitude has the highest values (from 0,790 to 0,892) only in the case of K500 functional connection with the parameters reflecting the content of aromatic structural fragments for the total set of the investigated samples and the total set of the investigated oils and natural bitumen. There is no correlation for individual fractions

ОБОБЩЕНИЕ РЕЗУЛЬТАТОВ ИССЛЕДОВАНИЙ МАГНИТНОЙ ВОСПРИИМЧИВОСТИ СОСТАВЛЯЮЩИХ БАЗАЛЬТОВОГО СЫРЬЯ

Объектом исследований являлись базальты Волыни, поскольку здесь ве-дется их интенсивная карьерная разработка. Внимание исследователей привле-кает уникальный состав базальтов и возможность их более рационального ис-пользования. В настоящее время базальт используется в основном как строи-тельный материал в виде щебня, в небольших количествах – для производства теплоизоляционной ваты. Однако исследования, выполненные геологами, уче-ными различных организаций, показали [1-4], что базальт является ценным ми-неральным сырьем и требует комплексной переработки для извлечения полез-ных компонентов, содержащихся в количествах, представляющих промышлен-ный интерес, и технологическую возможность их извлечения. Наличие приме-сей в массиве базальта в виде лавобрекчий и туфов не снижает актуальности и ценности идеи комплексной переработки, поскольку эти ингредиенты в своем составе содержат те же полезные компоненты, что и базальт. Основными из них являются самородная медь, железо и титан [4]. Более глубокие исследования показали, что в них содержатся окислы меди, редкие и ценные металлы, извле-чение которых требует более тонких технологий

Zurich Consensus: German Expert Opinion on the St. Gallen Votes on 15 March 2009 (11th International Conference at St. Gallen: Primary Therapy of Early Breast Cancer)

A German working group of 23 breast cancer experts discussed the results from the vote at this year's St. Gallen Consensus Conference on Primary Therapy for Early Breast Cancer ( March 11-14, 2009) and came up with some concrete recommendations for day-to-day therapeutic decisions in Germany. Due the fact that the concept of the St. Gallen Consensus Conference merely allows for a minimal consensus, the objective of the working group was to provide practice-related recommendations for day-to-day clinical decisions in Germany. One area of emphasis at St. Gallen was tumor biology as a starting point for reaching individual therapeutic decisions. Intensive discussion was necessary with respect to the clinical relevance of predictive and prognostic factors. A new addition to the area of systemic therapy was a first-ever discussion of the adjuvant administration of bisphosponates and the fact that therapy with trastuzumab in HER2 overexpressing breast cancer has been defined as the standard for neoadjuvant therapy. The value of taxanes as a component of (neo) adjuvant chemotherapy as well as the value of aromatase inhibitors for the endocrine adjuvant treatment of postmenopausal patients were affirmed

Zurich Consensus: Statement of German Experts on St. Gallen Conference 2011 on Primary Breast Cancer (Zurich 2011)

Every 2 years, the International Consensus Conference on the Treatment of Primary Breast Cancer takes place in St. Gallen. Given that the concept of the St. Gallen Consensus Conference mainly reflects an international opinion, it appears useful to adapt the results of the vote for everyday therapy in Germany. A German working group comprising 28 breast cancer experts, amongst whom there are 3 members of the international St. Gallen panel, has therefore commented on this year's St. Gallen Consensus Conference (2011) from the German viewpoint. The focus of interest of this year's St. Gallen Conference was tumour biology as the starting point for decisions regarding individual therapy. There was an intensive discussion in relation to the clinical relevance of predictive and prognostic factors and possible consequences for decisions regarding therapy. Therefore, questions concerning the indication for adjuvant chemotherapy focused especially on the significance of the molecular phenotype of the tumour. In addition, important points for discussion were also the value of complete axillary dissection and the use of accelerated complete breast irradiation

On the use of wavelet denoising and spike sorting techniques to process electroneurographic signals recorded using intraneural electrodes.

Among the possible interfaces with the peripheral nervous system (PNS), intraneural electrodes represent an interesting solution for their potential advantages such as the possibility of extracting spikes from electroneurographic (ENG) signals. Their use could increase the precision and the amount of information which can be detected with respect to other processing methods. In this study, in order to verify this assumption, thin-film longitudinal intrafascicular electrodes (tfLIFE) were implanted in the sciatic nerve of rabbits. Various sensory stimuli were applied to the hind limb of the animal and the elicited ENG signals were recorded using the tfLIFEs. These signals were processed to determine whether the different types of information can be decoded. Signals were wavelet denoised and spike sorted. Support vector machines were trained to use the spike waveforms found to infer the stimulus applied to the rabbit. This approach was also compared with previously used ENG-processing methods. The results indicate that the combination of wavelet denoising and spike sorting techniques can increase the amount of information extractable from ENG signals recorded with intraneural electrodes. This strategy could allow the development of more effective closed-loop neuroprostheses and hybrid bionic systems connecting the human nervous system with artificial devices

Intrafollicular and Circulating Concentrations of Leptin Do Not Predict the Outcome in IVF-ICSI Cycles

Leptin is involved not only in the regulation of food intake but also in other functions including reproduction. Because leptin has been demonstrated to influence ovarian steroidogenesis directly and leptin levels vary during the menstrual cycle and in stimulated cycles, we tested the hypothesis that serum or intrafollicular concentrations of leptin would correlate with reproductive outcomes in intracytoplasmic sperm injection cycles. Serum and follicular fluid samples were collected from 77 women undergoing ovarian stimulation, intracytoplasmic sperm injection and embryo transfer due to male factor infertility. The concentrations of total leptin, both in serum and in pooled follicular fluid samples, did not correlate with the number of oocytes, the fertilization rate or the embryo quality. Additionally, leptin concentrations did not differ between cycles that resulted in pregnancy and those that failed. These results raise objections to the prognostic value of leptin for the outcome of in vitro fertilization/intracytoplasmic sperm injection cycles