Abstract:Given a graph ( , ) G N E  , the Covering Salesman Problem (CSP) is to identify the minimum length tour "covering" all the nodes. More specifically, it seeks the minimum length tour visiting a subset of the nodes in N such that each node i not on the tour is within a predetermined distance d i of a node on the tour. In this paper, we define and develop a generalized version of the CSP, and refer to it as the Generalized Covering Salesman Problem (GCSP). Here, each node i needs to be covered at least i k times and there is a cost associated with visiting each node. We seek a minimum cost tour such that each node i is covered at least i k times by the tour. We define three variants of the GCSP. In the first case, each node can be visited by the tour at most once. In the second version, visiting a node i more than once is possible, but an overnight stay is not allowed (i.e., to revisit a node i, the tour has to visit another node before it can return to i). Finally, in the third variant, the tour can visit each node more than once consecutively. In this paper, we develop two local search heuristics to find high-quality solutions to the three GCSP variants. In order to test the proposed algorithms, we generated datasets based on TSP Library instances. Since the CSP and the Generalized Traveling Salesman Problem are special cases of the GCSP, we tested our heuristics on both of these two problems as well. Overall, the results show that our proposed heuristics find highquality solutions very rapidly.

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PURPOSE: Tension type headache (TTH) is one of the most prevalent types of headache. TTH is classified as episodic if it occurs on less than 15 days a month and as chronic if it occurs more often. Tension, anxiety and depression are some etiological factors for TTH which leads to work efficiency reduction. Today the interest in non-pharmacological methods is increasing; massage is one of these approaches which has no side effects. Aim of this study was to investigate the effects of neck Myofascial Release (MFR) techniques and exercise therapy on pain intensity and disability in patients with chronic tension-type headache.METHODS: This randomized clinical trial study was investigated on 30 females suffering from TTH. Participants were randomly assigned into two equal groups (n=15). The MFR group received neck MFR massage and exercise therapy four times a week for 3 weeks, each session lasting 45 minutes. Control group had no intervention. Outcomes were headache intensity and disability measured by numerical rating scale (NRS) and headache disability index (HDI), respectively. Data was analysed through independent and pair t-test.RESULTS: Between group comparison showed significant improvement of headache intensity and disability rate in MFR group (p<0.05) than control group (p=0.000).DISCUSSION: This study provides evidences that MFR technique and exercise therapy have significant effect on patients with TTH.