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Numerical metaheuristics are often tested on mathematical problems collected into a benchmark set. There are many benchmark sets, but the number of problems in a particular benchmark rarely exceeds 30, sometimes is much lower. The stopping condition is frequently based on the maximum number of function evaluations, commonly set to a single value, somehow related to the problem's dimensionality. However, the ranking of algorithms may highly depend on the number of allowed function evaluations. As a result, by changing the number of function evaluations, different algorithms may be promoted as the best ones. In the present study, we suggest that metaheuristics should rather be tested using independently four different numbers of maximum function evaluations that differ by orders of magnitude (e.g., 5.000, 50.000, 500.000, and 5.000.000 function calls). We recommend performing tests on both higher- and lower-dimensional versions of 72 problems from three well-known benchmark sets (CEC 2014, CEC 2017, CEC 2022). The ranking of algorithms based on each particular computational budget should be discussed separately. This way, various algorithms may show their strengths in shorter or longer searches and weaknesses in other cases, encouraging more nuanced discussion. We also show that the number of benchmark problems does matter: results based on larger sets of problems are much more frequently statistically significant than results based on a single small benchmark set. There is also a difference in the percentage of statistically significant results between tests performed with lower and higher numbers of allowed function calls. [ABSTRACT FROM AUTHOR]

The controlled destruction of the PIN diode detectors, SIEMENS SFH 870/F170 and SFH 871/F171, by the 35 MeV beam of the 12C and by 24 MeV of the 14N, respectively, was characterized using nuclear spectroscopy, the surface profile measurements, and the positron annihilation spectroscopy technique. The beam fluence was in the range of 1012-1014 ions/cm². It has been shown that the fluence of 1012 ions/cm2 of the 12C beam did not allow it to destroy the PIN diode detector. For this purpose, one needs the fluence of at least 4 × 1012 ions/cm² for the 14N ions beam and 2:2 × 1013 ions/cm² for the 12C ions one. The presence of divacancies in the irradiated sample was detected by the positron lifetimes measurements, with the fraction significantly higher for the 12C implanted sample. Furthermore, it was found that the surface roughness changed drastically following the implantation, i.e., the arithmetic average of profile height deviations from the mean surface of the 14N beam implanted sample is significantly higher than of that irradiated with the 12C ions and the reference one, and the surface average roughness was about 2-3 times higher. [ABSTRACT FROM AUTHOR]

For over twenty years there has been a constant trend for scientific research to be applied in everyday life and thus raise the standard of living and improve the quality of life of ordinary citizens. Since the beginning of the 21st century, the Heavy Ion Laboratory, in cooperation with the Nuclear Medicine Department of the Independent Public Central Clinical Hospital of the Warsaw Medical University at Banacha Street, has undertaken joint actions to introduce in Poland the diagnostic tests commonly known as positron emission tomography scans. This article presents a brief history of the establishment of the Radiopharmaceuticals Production and Research Center together with its equipment and research work. [ABSTRACT FROM AUTHOR]

A Coulomb-excitation measurement to study low-energy electromagnetic properties of 45Sc has been performed at the IUAC facility in New Delhi, India using a 70 MeV 32S projectile from the 15UD tandem accelerator. The preliminary value of the reduced transition probability B(E2, 11/2- ! 7/2-) and the resulting lifetime for the 11/2- state at 1237 keV were determined using the GOSIA code. [ABSTRACT FROM AUTHOR]

The low-energy electromagnetic structure of 110Cd was studied using safe-energy Coulomb excitation at the Heavy Ion Laboratory, University of Warsaw. The preliminary results on the quadrupole deformation of lowlying 0+ states in 110Cd are presented and compared to the recent beyond mean-field and General Bohr Hamiltonian calculations. [ABSTRACT FROM AUTHOR]

In order to gain further information on the electromagnetic properties of the low-lying states in 45Sc, a Coulomb excitation measurement was carried out at the IUAC, New Delhi. The 45Sc target nuclei were Coulomb excited by the 70 MeV 32S beam from the 15UD tandem accelerator. The -rays depopulating Coulomb excited states in 45Sc were detected by four Clover detectors in coincidence with the forward scattered ions. The main aim of the experiment was to determine the B(E3; 7=2- → 3=2+) and B(E3; 7=2- → 5=2+) transition probabilities, as well as the transitional electromagnetic matrix elements for low-lying intruder states. [ABSTRACT FROM AUTHOR]

Various benchmark sets have already been proposed to facilitate comparison between metaheuristics, or Evolutionary Algorithms. During the competition, typically algorithms are allowed either to run until the allowed number of function calls is exhausted (and one compares the quality of solutions found), or until a required objective function value is obtained (one compares the speed in reaching the required solution). During the last 20 years several problem sets were defined using the first approach. In this study, we test 73 optimization algorithms proposed between the 1960′s and 2022 on nine competitions based on four sets of problems (CEC 2011, CEC 2014, CEC 2017, and CEC 2020) with different dimensionalities. We intend to test the original versions of 73 algorithms "as they are", with control parameters proposed by the authors of the particular method. The recent benchmark set, CEC 2020, includes fewer problems and allows much more function calls than the former sets. As a result, one group of algorithms perform best on older, a different one on the more recent (CEC 2020) benchmark sets. Almost all algorithms that perform best on CEC 2020 set achieve moderate-to-poor performance on older sets, including real-world problems from CEC 2011. Algorithms that perform best on older sets are more flexible than those that perform best on CEC 2020 benchmark. The choice of the benchmark may have a crucial impact on the final ranking of algorithms. The lack of tuning may affect the results that were obtained in this study, hence it is highly recommended to repeat a similar large-scale comparison with control parameters of each algorithm tuned, best by different methods, separately for each benchmark set. [ABSTRACT FROM AUTHOR]

Abstract For about two decades Differential Evolution (DE) algorithms belong to the most successful optimization metaheuristics. Among plentiful DE versions proposed so far those that are based on mutation strategies and control parameter adaptation methods introduced within JADE and SHADE variants show especially encouraging performance. However, many modifications of JADE or SHADE are developed simultaneously by various researchers, and are rarely compared or discussed against each other. As most of JADE or SHADE-based variants are tested on recently introduced sets of artificial benchmark functions with a single, pre-specified maximum number of function calls, it remains unclear how they would perform on real-world problems, or when the number of allowed function calls differs from the standard values. In this study in-deep insight into the performance of twenty two JADE/SHADE-based variants on a large sets of artificial benchmarks and real-world problems is presented. The impact of the pre-assumed maximum number of function calls and the algorithm population size on the results is verified and discussed. Finally, overall comparison of algorithms that originate from JADE or SHADE against other kinds of metaheuristics is presented. The main aim of the study is to point out these among recently introduced JADE or SHADE-based operators that turn out to be especially successful, and to determine conditions under which they either achieve desired results or fail. [ABSTRACT FROM AUTHOR]

To determine the shape of 132Ba Coulomb excitation measurement has been performed at U-200P cyclotron at Heavy Ion Laboratory, University of Warsaw, Poland. A 32S beam of ~90 MeV energy has been bombarded on enriched 132Ba-target to Coulomb excite the latter nuclei. EAGLE gamma-ray spectrometer consisting of 15 single crystal HPGe detectors has been used to detect the deexcited gamma-rays from Coulomb excited Ba nuclei. The data has been collected using Particle-gamma coincidence technique for a period of seven days. The back scattered projectiles have been identified with 48 PiN diodes of 0.5 X 0.5 cm² active area mounted in a scattering chamber of ~5 cm radius called as ‘Munich chamber’. The energy states up to ~1127 keV energy have been populated in the interested 132Ba isotope. The preliminary results of the data analysis are presented here. [ABSTRACT FROM AUTHOR]

Low-lying excited states of 104Pd were investigated by means of Coulomb excitation using the 32S beam. Gamma-ray spectra resulting from the deexcitation of these levels were measured with the EAGLE gamma-ray spectrometer at the Heavy Ion Laboratory, University ofWarsaw. The first three excited states above the ground state up to 6+ level were populated alongwith the low-lying non-yrast states. Excitation of the 3- state at 2194 keV energy was also observed. [ABSTRACT FROM AUTHOR]

The Coulomb excitation experiment to study electromagnetic structure of low-lying states in 42Ca with a focus on a possible superdeformation in this nucleus was performed at the Laboratori Nazionali di Legnaro in Italy. Preliminary values of the determined quadrupole deformation parameters for both the ground state band and the presumed superdeformed band are presented. [ABSTRACT FROM AUTHOR]

The planning, history of construction, description of the equipment and the expected activity program of the University of Warsaw Radiopharmaceuticals Production and Research Centre are presented. [ABSTRACT FROM AUTHOR]

Coulomb excitation is the only experimental method that can measure quadrupole moments of short-lived excited states, thus providing information on nuclear shape. This paper presents data analysis techniques that were used to extract the diagonal matrix element of the Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. state in 100Mo. Influence of various methods of data subdivision and accuracy of the beam energy on the final result is discussed. Obtained quadrupole moment of the Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed state is compared to the one determined from earlier measurements. [ABSTRACT FROM AUTHOR]

The quadrupole shape evolution in heaviest stable Mo isotopes is studied in terms of the shape coexistence phenomenon occurrence in this region of nuclear chart. Quadrupole deformation parameters of the 96,98,100Mo isotopes in the low-lying (ground and excited) 0+ states were deduced using Coulomb excitation method. In all cases rich sets of electromagnetic reduced matrix elements were determined using the GOSIA code and then analysed using the Quadrupole Sum Rules formalism. Discussion of the experimental results in comparison with the predictions of microscopic calculations within the general quadrupole collective Bohr Hamiltonian model is presented for 100Mo. [ABSTRACT FROM AUTHOR]

The air2water model is a physically-based model in which major physical processes are parameterized. It allows to predict the surface lake temperature based solely on the time series of the air temperature. Due to its simplicity and very limited data requirements, it has found numerous applications around the globe. The air2water model defines the normalized depth of the well-mixed surface layer using a fixed parameter. This parameter is a threshold value that is set to 4 °C – the temperature of water with maximum density – for dimictic lakes, and to the minimum or to the maximum water temperature for warm or cold monomictic lakes, respectively. In this paper we propose to calibrate the threshold value as the ninth parameter of the model, instead of setting it fixed. We test the proposed approach on a set of 30-years long daily data from 22 lakes located in the lowland part of Poland and 25-years long daily data from the two Great Lakes – Huron and Eire. The proposed modification is very simple and improves the performance of the model, especially for winter-spring season, for the vast majority of lakes not only for the calibration, but also for the independent 8–10 years long validation data. [ABSTRACT FROM AUTHOR]

The weakening of the N = 28 shell closure and the development of deformation and shape coexistence were addressed in a low-energy Coulomb excitation experiment using a radioactive 44Ar beam from SPIRAL. The 21+ and one higher-lying state in 44Ar were excited on 208Pb and 109Ag targets at two different beam energies. From the collected data it will be possible to extract the B(E2) values between all observed states and to determine the quadrupole moment of the first 2+ state, providing information on the prolate or oblate character of the deformation. [ABSTRACT FROM AUTHOR]

Particle Swarm Optimization (PSO) is among the most universally applied population-based metaheuristic optimization algorithms. PSO has been successfully used in various scientific fields, ranging from humanities, engineering, chemistry, medicine, to advanced physics. Since its introduction in 1995, the method has been widely investigated, which led to the development of hundreds of PSO versions and numerous theoretical and empirical findings on their convergence and parameterization. However, so far there is no detailed study on the proper choice of PSO swarm size, although it is widely known that population size crucially affects the performance of metaheuristics. In most applications, authors follow the initial suggestion from 1995 and restrict the population size to 20–50 particles. In this study, we relate the performance of eight PSO variants to swarm sizes that range from 3 up to 1000 particles. Tests are performed on sixty 10- to 100-dimensional scalable benchmarks and twenty-two 1- to 216-dimensional real-world problems. Although results do differ for the specific PSO variants, for the majority of considered PSO algorithms the best performance is obtained with swarms composed of 70–500 particles, indicating that the classical choice is often too small. Larger swarms frequently improve efficiency of the method for more difficult problems and practical applications. For unimodal problems slightly lower swarm sizes are recommended for the majority of PSO variants, but some would still perform best with hundreds of particles. [ABSTRACT FROM AUTHOR]

The Coulomb excitation experiment to study electromagnetic properties of the heaviest stable Mo isotope, 100Mo, was performed using a 76 MeV 32S beam from the Warsaw cyclotron U-200P. Magnitudes and relative signs of 26 E1, El, E3, and M1 matrix elements coupling nine low-lying states in 100Mo were determined using the least-squares code GOSIA. Diagonal matrix elements (related to the spectroscopic quadrupole moments) of the 2f1+, 22+, and 23+ states as well as the 41+ state were extracted. The resulting set of reduced E2 matrix elements was complete and precise enough to obtain, using the quadrupole sum rules approach, quadrupole deformation parameters of 100Mo in its two lowest 0+ states: ground and excited. The overall deformation of the 0¹ and 0² states in 100Mo is of similar magnitude, in both cases larger compared to what was found for the neighboring isotopes 96Mo and 98Mo. At the same time, the asymetry parameters obtained for both states strongly differ, indicating a triaxial shape of the 100Mo nucleus in the ground state and a prolate shape in the excited 0+ state. Low-energy quadrupole excitations of the 100Mo nucleus were studied in the frame of the general quadrupole collective Bohr Hamiltonian model (GBH). The potential energy and inertial functions were calculated using the adiabatic time-dependent Hartree-Fock-Bogoliubov (ATDHFB) method starting from two possible variants of the Skyrme effective interaction: SHI and Sly4. The overall quadrupole deformation parameters resulting from the GBH calculations with the SLy4 variant of the Skyrme interaction are slightly closer to the experimentally obtained values than those obtained using SUI. [ABSTRACT FROM AUTHOR]

Excited states of the 146Tb nucleus have been studied using γ-ray and electron spectroscopy in off-beam and in-beam modes following 112Sn(40Ar,3n3p) reaction with the use of the OSIRIS-II, HPGe detector array and the conversion electron spectrometer. The multipolarity of the 343 keV transition deexciting the (7-) level in 146Tb shows mainly an E2 nature and the first excited state above the 23 s isomer is assigned as a (5-,6-) state. The log?ft values have been deduced for 11 β+/EC transitions populating excited states in 146Gd. The systematic behavior of spins and parities of the long-lived levels at 0+x keV and the first excited states above them in the N=81 isotones 146Tb, 148Ho, and 150Tm is discussed. [ABSTRACT FROM AUTHOR]

The level structure of 231Pa was investigated by Coulomb excitation using 148 MeV 32S and 255, 260 and 261 MeV 58Ni projectiles and the NORDBALL detector array. The 1/2[530] ground-state rotational band was excited up to spin 39/2−. The 3/2[651] band, established up to spin 37/2+, was observed to be populated apart from direct Coulomb excitation by the de-excitation of the 1/2[530] band. The 1/2[400] band could be followed up to spin 23/2+. Weak excitation of the bands 5/2[642], 5/2[512], 3/2[532] and 3/2[521] was seen up to spins 11/2+, 15/2−, 9/2− and 9/2−, respectively. Matrix elements were extracted from the γ-ray yields with the help of the semi-classical Coulomb-excitation least-squares search code GOSIA. The level scheme and transition intensities were analyzed in the framework of the quasiparticle-plus-phonon model including Coriolis-coupling (QPMC). [Copyright &y& Elsevier]

Collective structures in 180Ta built on the meta-stable Kπ=9− high-spin isomer were investigated using two types of Coulomb excitation experiments. In-beam studies identify γ-vibrational bands with typical bandhead E2 excitation strengths of 6 Weisskopf units (W.u.). Coulomb activation of the 180Ta ground state was measured with 36S and 64Ni projectiles using thin targets. The excitation functions and the 180Ta recoil angular distributions favor a Kπ=7+ octupole vibration at Ex=1155(40) keV as intermediate state in the population of the ground state. [Copyright &y& Elsevier]

Background: The γ softness of 136Nd makes it possible to study the shape changes induced by two-proton or two-neutron excitation. Purpose: We measure the lifetimes of two-quasiparticle states of the bands based on the 10+ states at 3296 and 3279 keV to investigate the shape change induced by the alignment of two protons or two neutrons in the h11/2 orbital. Methods: The recoil-distance Doppler shift method was used for the study of 136Nd studies, which was formed by the fusion reaction 120Sn(20Ne,4n)136Nd, at Ebeam=85 MeV. Calculations were performed within the microscopic-macroscopic approach, based on the deformed Woods-Saxon single-particle potential and the Yukawa-plus-exponential macroscopic energy. Results: The lifetime of the 10+ state at 3279 keV of 136Nd was measured to be T10+1/2=1.63(9) ns. The lifetimes of the 2+ state at 374 keV and of the 12+ state at 3686 keV of the ground band were also measured to be T2+1/2=26.5(14) ps and T12+1/2=22.5(14) ps. Conclusions: The measured lifetime of 10+ the state at 3279 keV together with other observables confirm the structure change in 136Nd. A rather small reduced hindrance of the electromagnetic decay of the 10+ state at 3279 keV would be consistent with its K-mixed character. [ABSTRACT FROM AUTHOR]

In a series of Coulomb excitation experiments the first excited 2+ states in semimagic 112,116,118,120,122,124Sn isotopes were excited using a 58Ni beam at safe Coulomb energy. The B(E2; 0+→2+) values were determined with high precision (~3%) relative to 58Ni projectile excitation. These results disagree with previously reported B(E2↑) values [A. Jungclaus et al., Phys. Lett. B 695, 110 (2011).] extracted from Doppler-shift attenuation lifetime measurements, whereas the reported mass dependence of B(E2↑) values is very similar to a recent Coulomb excitation study [J. M. Allmond et al., Phys. Rev. C 92, 041303(R) (2015)]. The stable Sn isotopes, key nuclei in nuclear structure, show no evidence of reduced collectivity and we, thus, reconfirm the nonsymmetric behavior of reduced transition probabilities with respect to the midshell A=116. [ABSTRACT FROM AUTHOR]