13,172 research outputs found
Optimal aeroassisted orbital transfer with plane change using collocation and nonlinear programming
The fuel optimal control problem arising in the non-planar orbital transfer employing aeroassisted technology is addressed. The mission involves the transfer from high energy orbit (HEO) to low energy orbit (LEO) with orbital plane change. The basic strategy here is to employ a combination of propulsive maneuvers in space and aerodynamic maneuvers in the atmosphere. The basic sequence of events for the aeroassisted HEO to LEO transfer consists of three phases. In the first phase, the orbital transfer begins with a deorbit impulse at HEO which injects the vehicle into an elliptic transfer orbit with perigee inside the atmosphere. In the second phase, the vehicle is optimally controlled by lift and bank angle modulations to perform the desired orbital plane change and to satisfy heating constraints. Because of the energy loss during the turn, an impulse is required to initiate the third phase to boost the vehicle back to the desired LEO orbital altitude. The third impulse is then used to circularize the orbit at LEO. The problem is solved by a direct optimization technique which uses piecewise polynomial representation for the state and control variables and collocation to satisfy the differential equations. This technique converts the optimal control problem into a nonlinear programming problem which is solved numerically. Solutions were obtained for cases with and without heat constraints and for cases of different orbital inclination changes. The method appears to be more powerful and robust than other optimization methods. In addition, the method can handle complex dynamical constraints
Production of large transverse momentum dileptons and photons in , and collisions by photoproduction processes
The production of large dileptons and photons originating from
photoproduction processes in , and collisions is calculated. We
find that the contribution of dileptons and photons produced by photoproduction
processes is not prominent at RHIC energies. However, the numerical results
indicate that the modification of photoproduction processes becomes evident in
the large region for , and collisions at LHC energies.Comment: 10 figure
Real photons produced from photoproduction in collisions
We calculate the production of real photons originating from the
photoproduction in relativistic collisions. The
Weizscker-Williams approximation in the photoproduction is
considered. Numerical results agree with the experimental data from
Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC). We find
that the modification of the photoproduction is more prominent in large
transverse momentum region.Comment: 2 figure
Object Contour and Edge Detection with RefineContourNet
A ResNet-based multi-path refinement CNN is used for object contour
detection. For this task, we prioritise the effective utilization of the
high-level abstraction capability of a ResNet, which leads to state-of-the-art
results for edge detection. Keeping our focus in mind, we fuse the high, mid
and low-level features in that specific order, which differs from many other
approaches. It uses the tensor with the highest-levelled features as the
starting point to combine it layer-by-layer with features of a lower
abstraction level until it reaches the lowest level. We train this network on a
modified PASCAL VOC 2012 dataset for object contour detection and evaluate on a
refined PASCAL-val dataset reaching an excellent performance and an Optimal
Dataset Scale (ODS) of 0.752. Furthermore, by fine-training on the BSDS500
dataset we reach state-of-the-art results for edge-detection with an ODS of
0.824.Comment: Keywords: Object Contour Detection, Edge Detection, Multi-Path
Refinement CN
Trauma-related psychological disorders among Palestinian children and adults in Gaza and West Bank, 2005-2008
BACKGROUND: Trauma from war and violence has led to psychological disorders in individuals living in the Gaza strip and West Bank. Few reports are available on the psychiatric disorders seen in children and adolescents or the treatment of affected populations. This study was conducted in order to describe the occurrence and treatment of psychiatric disorders in the Palestinian populations of the Gaza strip and Nablus district in the West Bank. METHODS: From 2005 to 2008, 1369 patients aged more than 1 year were identified through a local mental health and counseling health network. All were clinically assessed using a semi-structured interview based on the DSM-IV-TR criteria. RESULTS: Among 1254 patients, 23.2% reported post-traumatic stress disorder [PTSD], 17.3% anxiety disorder (other than PTSD or acute stress disorder), and 15.3% depression. PTSD was more frequently identified in children < or = 15 years old, while depression was the main symptom observed in adults. Among children < or = 15 years old, factors significantly associated with PTSD included being witness to murder or physical abuse, receiving threats, and property destruction or loss (p < 0.03). Psychological care, primarily in the form of individual, short-term psychotherapy, was provided to 65.1% of patients, with about 30.6% required psychotropic medication. Duration of therapy sessions was higher for children < or = 15 years old compared with adults (p = 0.05). Following psychotherapy, 79.0% had improved symptoms, and this improvement was significantly higher in children < or = 15 years old (82.8%) compared with adults (75.3%; p = 0.001). CONCLUSION: These observations suggest that short-term psychotherapy could be an effective treatment for specific psychiatric disorders occurring in vulnerable populations, including children, living in violent conflict zones, such as in Gaza strip and the West Bank
Managerial Valuation of Applicant Credentials and Personal Traits in Hiring Decisions
We study how managers value applicant credentials and personal traits in hiring decisions. Using the ordered probit model, we confirm previous results – managers rank applicant traits higher than credentials. However, we also uncover patterns not previously observed – managerial valuations of some of these characteristics are dependent on managers' perception of the overall state of the economy, on firm and immediate workplace characteristics, and on managers' personal characteristics. Manager valuations of credentials vary with a large number of factors; this is not so for applicant personal traits. This is not surprising as most managers view the five traits considered "as extremely important."personality, credentials, hiring practices, ordered probit
Quantum mechanical photon-count formula derived by entangled state representation
By introducing the thermo entangled state representation, we derived four new
photocount distribution formulas for a given density operator of light field.
It is shown that these new formulas, which is convenient to calculate the
photocount, can be expressed as such integrations over Laguree-Gaussian
function with characteristic function, Wigner function, Q-function, and
P-function, respectively.Comment: 5 pages, no figur
Kandungan Gizi dan Bahan Aktif Fenol Daun Bangun-Bangun (Coleus Amboinicus L.) pada Metoda Pengeringan yang Berbeda
Tanaman bangun-bangun (Coleus amboinicus L.) mengandung kalium, karbohidrat, dan energi yang tinggi, serta minyak atsiri dengan kandungan carvakrol, isoprofil-o-kresol dan fenol. Secara farmakologi, tanaman ini mengandung beberapa bahan aktif yang bersifat menghilangkan sakit, penurun panas, dan antiseptik, penyegar, dan penambah semangat. Cara pengeringan berpengaruh terhadap tanaman, selain itu bahwa pengeringan bahan tanaman yang kurang tepat akan merusak komponen bahan aktif sehingga menurunkan mutunya. Penelitian ini dilakukan di Politeknik Pertanian Negeri Payakumbuh, bahan yang digunakan adalah daun bangun-bangun segar yang dikeringkan dengan 4 (empat) cara pengeringan yaitu: kipas angin, oven, udara dan matahari. Daun bangun-bangun yang telah dikeringkan selanjutnya dianalisa di laboratorium kimia. Percobaan dilakukan menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 5 ulangan. Hasil analisa laboratorium kimia menunjukkan bahwa perlakuan metode pengeringan daun bangun-bangun berpengaruh sangat nyata pada kandungan protein kasar, serat kasar dan fenol. Pengeringan kering matahari menunjukkan kadar protein tertinggi (20,48%) dan pengeringan kipas angin menunjukkan kadar protein terendah (12,65%). Pengeringan kering oven menunjukkan kadar serat kasar tertinggi (17,21%) dan kipas angin menunjukkan kadar serat kasar terendah (13,05%). Pengeringan kipas angin menunjukkan kadar total fenol tertinggi (8.400 ppm) dan oven menunjukkan terendah (2.100 ppm)
Generalized thermo vacuum state derived by the partial trace method
By virtue of the technique of integration within an ordered product (IWOP) of
operators we present a new approach for deriving generalized thermo vacuum
state which is simpler in form that the result by using the Umezawa-Takahashi
approach, in this way the thermo field dynamics can be developed. Applications
of the new state are discussed.Comment: 5 pages, no figure, revtex
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