The Approximation Ratio of the 2-Opt Heuristic for the Euclidean Traveling Salesman Problem

The 2-Opt heuristic is a simple improvement heuristic for the Traveling Salesman Problem. It starts with an arbitrary tour and then repeatedly replaces two edges of the tour by two other edges, as long as this yields a shorter tour. We will prove that for Euclidean Traveling Salesman Problems with n cities the approximation ratio of the 2-Opt heuristic is ?(log n / log log n). This improves the upper bound of O(log n) given by Chandra, Karloff, and Tovey [Barun Chandra et al., 1999] in 1999

The Best of Times is Now

Although researchers have found that cognitive temporal structures differ across cultures, few have studied the cognitive temporal structures of subcultures within them — and in a consumer behavior context. Integrating the literature on time, culture and consumer behavior, this study empirically tests for variations in time perceptions between the dominant heterosexual culture and the gay subculture. Results indicate that there may be socio-cultural elements of a subculture that produce variation in a subculture's temporal cognitive structure. Compared to heterosexuals, gays are more present-oriented. This finding is then applied to predict differences in consumer behavior

Polyolefine Composites Reinforced by Rice Husk and Saw Dust

Due to the global demand for fibrous light-weight materials, research on composites reinforced with plant materials has increased. Natural fiber reinforced composites offer several advantages: light weight, competitive specific mechanical properties, easy processing, large volume availability, low cost, and low environmental footprint. Especially, using agricultural wastes such as rice husk, saw dust etc. as fillers/fibres in composites provides the chance to improve material properties while improving their sustainability. In the present work, rice husk and saw dust were chosen as fillers for their differing morphology, aspect ratios, and difference of structure. As matrices, polyethylene (PE) and polypropylene (PP) were studied, either neat or modified with maleic anhydride grafted PP/PE as coupling agent or compatibilizer between hydrophobic matrices and hydrophilic bio-fillers. The bending modulus is improved due to filler addition. In presence of compatibilizer, the improved interfacial interaction leads to improved bending and tensile strength as well as toughness. Furthermore, the influence of the filler and compatibilizer on composite properties such as hardness, dynamic mechanical behaviour, thermal expansion, thermal degradation, melting and crystallisation behaviour are presented

Leadership in “Confucian Asia”: a three-country study of justice, trust, and transformational leadership

Increasing globalization and the economic uncertainty inherent in the recent financial crisis have strained the already tenuous commitment of many employees, making followers’ perceptions of justice and trust more critical now than ever before in retaining a loyal workforce. A model of leadership, organizational justice, trust, and work outcomes such as commitment and satisfaction, similar to the one tested in the US, was extended to three countries in the so-called “Confucian Asian Cluster” in the Global Leadership and Organizational Behavior Effectiveness (GLOBE) study. Data were collected from executives in: Mainland China (N¼131), Singapore (N¼246), and Taiwan (N¼99). Results indicate that transformational leaders in the Mainland build trust through procedural justice and distributive justice; trust in the leader is, in turn, related to job satisfaction and commitment. Transformational leaders in Singapore work indirectly through both distributive and procedural justice mechanisms to build trust and work outcomes, and also directly through trust to influence satisfaction and commitment. Finally, leaders in Taiwan use transformational leadership to influence procedural justice, trust, commitment, and satisfaction. Implications are discussed for leaders attempting to foster committed and satisfied workers in light of challenging economic circumstances

Laccase-Enzyme Treated Flax Fibre for Use in Natural Fibre Epoxy Composites

Natural fibres have a high potential as reinforcement of polymer matrices, as they combine a high specific strength and modulus with sustainable production and reasonable prices. Modifying the fibre surface is a common method to increase the adhesion and thereby enhance the mechanical properties of composites. In this study, a novel sustainable surface treatment is presented: the fungal enzyme laccase was utilised with the aim of covalently binding the coupling agent dopamine to flax fibre surfaces. The goal is to improve the interfacial strength towards an epoxy matrix. SEM and AFM micrographs showed that the modification changes the surface morphology, indicating a deposition of dopamine on the surface. Fibre tensile tests, which were performed to check whether the fibre structure was damaged during the treatment, showed that no decrease in tensile strength or modulus occurred. Single fibre pullout tests showed a 30% increase in interfacial shear strength (IFSS) due to the laccase-mediated bonding of the coupling agent dopamine. These results demonstrate that a laccase + dopamine treatment modifies flax fibres sustainably and increases the interfacial strength towards epoxy

Hållbarhetsarbete som verktyg för ökad ekonomisk lönsamhet i konfektionsbranschen

Title: Sustainability as a tool for obtaining increased profitability in the business of ready-made clothing Seminar date: 2013-06-05 Course: Business Administration: Bachelor Degree Project in Financial and Management Accounting at the Undergraduate Level, 15 ECTS Authors: Johan Axelsson, Jacob Brodowsky, Henrik Ohlsson Advisor: Rolf Larsson Five key words: The Boomerang Effect, sustainability, the Clothing Industry, profitability, Triple Bottom Line Purpose: The purpose of this thesis is to analyze if, and in that case how, a company dealing with ready-made clothing can use sustainability as a means of increasing profitability. Methodology: The authors have carried out a qualitative case study on Boomerang, a company dealing with ready-made clothing. This was based on a single case design with predominantly an inductive approach. The study is based on semi-structured interviews, as well as printed sources. Theoretical perspectives: The theoretical underframe of this study is based on theories on Corporate Responsibility, namely sustainability, CSR and Triple Bottom Line. Empirical foundation: The empirical foundation is based on semi-standardized interviews with key persons at Boomerang, a company dealing with ready-made clothing. In addition, documents regarding the company’s sustainability concept, the Boomerang Effect, have been utilized as complements to the interview responses. Conclusions: By using their sustainability concept the Boomerang Effect, Boomerang has shown that a company dealing with ready-made clothing can utilize sustainability to achieve profitability. Boomerang has proven this by taking care of used clothes as well as fabric wastage and in this way creating and selling products with a financial value, and which at the same time make for a sustainable development. By working with the Boomerang Effect, Boomerang fulfills the criteria for sustainability by heeding financial, social and environmental aspects

Negative phase time for Scattering at Quantum Wells: A Microwave Analogy Experiment

If a quantum mechanical particle is scattered by a potential well, the wave function of the particle can propagate with negative phase time. Due to the analogy of the Schr\"odinger and the Helmholtz equation this phenomenon is expected to be observable for electromagnetic wave propagation. Experimental data of electromagnetic wells realized by wave guides filled with different dielectrics confirm this conjecture now.Comment: 10 pages, 6 figure

Investigating the influence of professor characteristics on student satisfaction and dissatisfaction: a comparative study

This research uses the Kano model of satisfaction to investigate professor characteristics that create student satisfaction as well as those attributes that can cause their dissatisfaction. Kano questionnaires were handed out to 104 undergraduate students at a university in the Southwest and to 147 undergraduate students at a university in the Midwest of the United States. The two resulting Kano maps show the same delighting attributes although other satisfaction attributes are also similar. The findings reveal the importance of the personality of professors and the characteristics of professors that (a) are desired by students, (b) are not desired by students, (c) affect student satisfaction the most, and (d) affect satisfaction the least. The results also demonstrate how professors and universities can focus attention on those attributes most likely to influence satisfaction. No attributes of professors are classified as basic or taken for granted factors by students, although three attributes are excitement factors that have the potential to delight students. The findings illustrate that there is a set of multiple attributes that professors need to possess for satisfying student–professor classroom service encounters. Student populations appear to show strong similarities in their preferences for characteristics of professors that lead to satisfaction and dissatisfaction outcomes

On Superluminal motions in photon and particle tunnelings

It is shown that the Hartman-Fletcher effect is valid for all the known expressions of the mean tunnelling time, in various nonrelativistic approaches, for the case of finite width barriers without absorption. Then, we show that the same effect is not valid for the tunnelling time mean-square fluctuations. On the basis of the Hartman-Fletcher effect and the known analogy between photon and nonrelativistic-particle tunnelling, one can explain the Superluminal group-velocities observed in various photon tunnelling experiments (without violation of the so-called "Einstein causality").Comment: standard LaTeX file; accepted for publication in Phys. Lett.