4,761 research outputs found
Decomposition by Successive Convex Approximation: A Unifying Approach for Linear Transceiver Design in Heterogeneous Networks
We study the downlink linear precoder design problem in a multi-cell dense
heterogeneous network (HetNet). The problem is formulated as a general
sum-utility maximization (SUM) problem, which includes as special cases many
practical precoder design problems such as multi-cell coordinated linear
precoding, full and partial per-cell coordinated multi-point transmission,
zero-forcing precoding and joint BS clustering and beamforming/precoding. The
SUM problem is difficult due to its non-convexity and the tight coupling of the
users' precoders. In this paper we propose a novel convex approximation
technique to approximate the original problem by a series of convex
subproblems, each of which decomposes across all the cells. The convexity of
the subproblems allows for efficient computation, while their decomposability
leads to distributed implementation. {Our approach hinges upon the
identification of certain key convexity properties of the sum-utility
objective, which allows us to transform the problem into a form that can be
solved using a popular algorithmic framework called BSUM (Block Successive
Upper-Bound Minimization).} Simulation experiments show that the proposed
framework is effective for solving interference management problems in large
HetNet.Comment: Accepted by IEEE Transactions on Wireless Communicatio
Probing dark particles indirectly at the CEPC
When dark matter candidate and its parent particles are nearly degenerate, it
would be difficult to probe them at the Large Hadron Collider directly. We
propose to explore their quantum loop effects at the CEPC through the golden
channel process . We use a renormalizable toy model
consisting of a new scalar and a fermion to describe new physics beyond the
Standard Model. The new scalar and fermion are general multiplets of the
symmetry, and couple to the muon lepton through Yukawa
interaction. We calculate their loop contributions to anomalous
and couplings which can be applied to many new
physics models. The prospects of their effects at the CEPC are also examined
assuming a 0.002 accuracy in the cross section measurement
Psychological crisis intervention for the family members of patients in a vegetative state
OBJECTIVES: Family members of patients in a vegetative state have relatively high rates of anxiety and distress. It is important to recognize the problems faced by this population and apply psychological interventions to help them. This exploratory study describes the psychological stress experienced by family members of patients in a vegetative state. We discuss the effectiveness of a psychological crisis intervention directed at this population and offer suggestions for future clinical work. METHODS: A total of 107 family members of patients in a vegetative state were included in the study. The intervention included four steps: acquisition of facts about each family, sharing their first thoughts concerning the event, assessment of their emotional reactions and developing their coping abilities. The Symptom Check List-90 was used to evaluate the psychological distress of the participants at baseline and one month after the psychological intervention. Differences between the Symptom Check List-90 scores at the baseline and follow-up evaluations were analyzed. RESULTS: All participants in the study had significantly higher Symptom Check List-90 factor scores than the national norms at baseline. There were no significant differences between the intervention group and the control group at baseline. Most of the Symptom Check List-90 factor scores at the one-month follow-up evaluation were significantly lower than those at baseline for both groups; however, the intervention group improved significantly more than the control group on most subscales, including somatization, obsessive-compulsive behavior, depression, and anxiety. CONCLUSION: The results of this study indicate that the four-step intervention method effectively improves the mental health of the family members who received this treatment and lessens the psychological symptoms of somatization, obsessive-compulsive behavior, depression and anxiety
Submerzni uzgoj gljiva u bioreaktorima – izazovi, dostignuća i budućnost proizvodnje
Medicinal mushrooms have profound health-promoting benefits. Recently, a number of substances of mushroom origin have been isolated, identified and shown to have physiological activities, such as antitumor, immunomodulating, cardiovascular, antihypercholesterolemia, antibacterial, antiviral, antiparasitic, hepatoprotective, and antidiabetic activities. Currently, commercial products from medicinal mushrooms are mostly obtained through the field-cultivation of the fruiting body. However, in this case it is difficult to control the quality of the final product. Submerged fermentation of the mycelial form of mushroom-producing fungi has received much attention as a promising alternative for efficient production of the biomass of medicinal mushrooms and their active metabolites. However, in order for the production to be successful at industrial scale, various technical problems need to be solved, including characterization of the variations that occur during the submerged cultivation of mushrooms in bioreactors and their effects on growth and product formation. This review outlines the major factors that affect the submerged cultivation of mushrooms in bioreactors, including oxygen supply, shear and mixing, morphology and rheology, as well as two-stage cultivation strategies and high-cell-density cultivation strategies such as fed-batch fermentation.Medicinske gljive pozitivno djeluju na ljudsko zdravlje. U novije vrijeme izolirane su brojne tvari iz gljiva koje utječu na fiziološke procese i imaju antitumorski, imunomodulacijski i kardiovaskularni učinak, snizuju kolesterol, imaju antibakterijski, antivirusni, antiparazitski i hepatoprotektivni učinak i sprečavaju pojavu dijabetesa. Komercijalni proizvodi dobivaju se uzgojem medicinskih gljiva na polju. Međutim, tim se postupkom teško kontrolira kakvoća gotovog proizvoda. Submerzna fermentacija micelija gljiva moguća je alternativa za uspješnu proizvodnju biomase medicinskih gljiva i njihovih aktivnih metabolita. Međutim, da bi se postigla uspješna industrijska proizvodnja, treba riješiti razne tehničke probleme, između ostalog odrediti odstupanja pri submerznom uzgoju gljiva u bioreaktorima i njihov utjecaj na rast i formiranje gotovog proizvoda. U ovom se revijalnom prikazu razmatraju glavni faktori utjecaja na submerzni uzgoj gljiva u bioreaktorima, a to su opskrba kisikom, posmično naprezanje i miješanje, te morfologija i reologija, opisuje strategija uzgoja gljiva u dvije faze te proizvodnja stanica velike gustoće šaržnom fermentacijom
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