Efficient Sample Location Selection for Query Zone in Geo-Social Networks

While promoting a business or activity in geo-social networks, the geographical distance between its location and users is critical. Therefore, the problem of Distance-Aware Influence Maximization (DAIM) has been investigated recently. The efficiency of DAIM heavily relies on the sample location selection. Specifically, the online seeding performance is sensitive to the distance between the promoted location and its nearest sample location, and the offline precomputation performance is sensitive to the number of sample locations. However, there is no work to fully study the problem of sample location selection for DAIM in geo-social networks. To do this, we first formalize the problem under a reasonable assumption that a promoted location always adheres to the distribution of users (query zone). Then, we propose two efficient location sampling approaches based on facility location analysis, which is one of the most well-studied areas of operations research, and these two approaches are denoted by Facility Location based Sampling (FLS) and Conditional Facility Location Based Sampling (CFLS), respectively. FLS conducts one-time sample location selection, and CFLS extends the one-time sample location selection to a continuous process, so that an online advertising service can be started immediately without sampling a lot of locations. Our experimental results on two real datasets demonstrate the effectiveness and efficiency of the proposed methods. Specifically, both FLS and CFLS can achieve better performance than the existing sampling methods for the DAIM problem, and CFLS can initialize the online advertising service in a matter of seconds and achieve better objective distance than FLS after sampling a large number of sample locations.

High-Precision and High-Resolution Synchrosqueezing Transform via Time-Frequency Instantaneous Phases

Synchrosqueezing transform (SST) can effectively improve time-frequency precision and resolution by squeezing time-frequency spectra via instantaneous frequencies, and it has been applied in many diverse disciplines; however, the precision of estimated instantaneous frequencies during SST is usually affected by the time-sample interval of the inputted signal; this usually leads to low-precision or inaccurate SST results and limits its further application. To obtain high-precision and high-resolution SST results with high efficiency, we propose a high-precision and high-resolution SST via time-frequency instantaneous phases (HSST); in HSST, time-frequency instantaneous phases with period-jumps removal are used for high-precision instantaneous frequencies estimation and SST. Two synthetic signal examples show that HSST can minimize the impact of the time-sample interval to achieve high-precision and high-resolution SST results with high efficiency. A real 3D seismic data application demonstrates that HSST has fantastic performance in time-frequency precision and resolution enhancement, and it can be widely used in digital signals processing and interpretation fields.

Simultaneously computing the 3D dip attributes for all the time samples of a seismic trace

The seismic dip attribute is regularly used to aid structural interpretation and is commonly adopted as a compulsory input for computing other seismic geometric attributes. One disadvantage of current dip computation algorithms is that interpreters compute the dip attribute time sample by time sample and do not consider the relationship between dip values of nearby samples. The classic convolution theory suggests one formation boundary should have the corresponding seismic event. However, the seismic wavelet always has a certain time duration. As a result, one formation boundary has a corresponding seismic event that consists of several time samples. Ideally, the time samples, which belong to the same boundary, should have approximately the same dip attributes. In this research, a sample by sample computation procedure is treated as an independent optimisation procedure. Then, simultaneously computing the seismic dip of time samples of one seismic trace can be regarded as a multi-objective optimisation procedure. The proposed method is based on analysing features of seismic waveform within user-defined windows. Considering that nearby time samples should have continuous dip values, we the dynamic time warping to simultaneously compute seismic reflectors’ dip values of a seismic trace. We applied our method to a field seismic data to demonstrate its effectiveness.

Studying the Effect of Potassium Amyl Xanthate Surfactant on Fe, Cu and U Ions for the Pretreatment of Abu Zeneima Sulphate Leach Liquor

In this study, batch experiments were performed to study the behavior of potassium amyl xanthate surfactant on Fe, Cu and U ions for the pretreatment of Abu Zeneima sulphate leach liquor. Various parameters, such as amount of potassium amyl xanthate, pH, stirring time, sample volume to potassium amyl xanthate mass (v/m ratio) and temperature were tested to determine the optimum conditions. The numerical results obtained support the experimental data on decreasing the iron and copper values where 0.1 g potassium amyl xanthate could remove 86.8 mg Fe and 0.98 mg Cu from the studied sulphate solution with no effect on uranium content. FTIR spectroscopy and XRF analysis were used for investigation.

Simulating the procedure of manual seismic horizon picking

Manual seismic horizon picking is the least efficient interpretation technique in terms of time and effort. The loop-tie is a key “element” and the most time-consuming task in manual horizon picking, which ensures the accuracy of horizon picking. Autopicking techniques have been used since the early 1980s. However, there are few studies simulating the procedure of manual seismic horizon picking and quantitatively evaluating the autopicked horizons. In our proposed method, we perform autopicking on inline and crossline seismic vertical slices independently, similar to the manual horizon picking procedure. We then evaluate the picked horizons using a loop-tie step similar to the loop-tie checking in manual horizon picking. To simulate the loop-tie step in manual picking, we define two dip attributes for each time sample of seismic traces, which are the “left” and “right” reflector dips. We only preserve the portions of the tracked horizons that meet the defined loop-tie checking. Next, we merge the tracked horizons centered at the seeded seismic traces. The two-way traveltime of the merged horizons functions as a “hard” control for the final step of autopicking. Finally, we use the seismic dip attribute to track the horizons over the seismic survey under the hard controls. The real data demonstrate that our algorithm can extract accurate horizons near discontinuities such as faults and unconformities.

Epsilon local rigidity and numerical algebraic geometry

A well-known combinatorial algorithm can decide generic rigidity in the plane by determining if the graph is of Pollaczek–Geiringer–Laman type. Methods from matroid theory have been used to prove other interesting results, again under the assumption of generic configurations. However, configurations arising in applications may not be generic. We present Theorem 4.2 and its corresponding Algorithm 1 which decide if a configuration is [Formula: see text]-locally rigid, a notion we define. A configuration which is [Formula: see text]-locally rigid may be locally rigid or flexible, but any continuous deformations remain within a sphere of radius [Formula: see text] in configuration space. Deciding [Formula: see text]-local rigidity is possible for configurations which are smooth or singular, generic or non-generic. We also present Algorithms 2 and 3 which use numerical algebraic geometry to compute a discrete-time sample of a continuous flex, providing useful visual information for the scientist.

Rapid and Sensitive Method for Extraction of Plicosepalus acacia with Determination of Its Main Polyphenolic Compounds Using Validated HPLC

Matrix solid phase dispersion (MSPD) trailed by HPLC is a quick and fruitful technique utilized for fortitude of flavonoids such as Catechin, Kaempferol, Quercetin, and Rutin existing in P. acacia. The trial parameters that influenced the extraction potential (comprising the mass ratio of sample to the dispersant, nature of dispersant, and the nature of elution solvent and its volume) were examined and optimized. These MSPD optimized parameters regulated are as follows: 8 mL of methanol was utilized as elution solvent, silica gel/sample mass ration was selected to be 2 : 1, and dispersing sorbent was silica gel. The technique retrievals were regulated to be “from 96.87 to 100.54%” and the RSDs from 1.24 to 4.45%. The product of extract obtained by MSPD method was larger than that of other methods, i.e., sonication extraction or traditional reflux with lessened necessities on time, sample, and solvent.

Pengaruh Bermain Lempar Tangkap Bola Terhadap Keterampilan Motorik Kasar Anak Usia 5 – 6 Tahun Di TK Melbourn

Permasalahan pada penelitian ini adalah kurangnya keterampilan motorik kasar anak sehingga menyebabkan anak mengalami hambatan, hambatan yang terjadi disebabkan karena pembelajaran motorik kasar pada sekolah belum dilakukan secara optimal, kurang dalam melibatkan aktifitas fisik anak, anak cenderung aktif terhadap kegiatan bermain, anak hanya berlari kesana kesini dan bermain seadanya, anak kurang mampu melakukan praktik bermain melempar dan menangkap bola, meskipun ada beberapa anak yang sudah bisa melakukan lempar tangkap bola, namun masih banyak anak yang masih terlihat kaku dan masih membutuhkan bantuan guru, melakukan gerakan dengan mengikuti arahan-arahan guru. Tujuan penelitian ini adalah untuk mengetahui pengaruh permainan lempar tangkap bola terhadap keterampilan motorik kasar kelompok B di TK Melbourn. Jenis penelitian ini adalah eksperimen, desain yang digunakan dalam penelitian ini adalah Quasi Exsperimental Design dengan bentuk the equivalent time sample design. Sampel penelitian ini adalah anak kelompok B2 yang berjumlah 15 orang. Teknik pengumpulan data menggunakan uji normalitas, dan uji hipotesis (Uji-t).Hasil analisis data observasi akhir keterampilan motorik kasar pada anak dengan menggunakan uji normalitas diketahui bahwa data tidak diberi perlakuan Lhitung <Ltabel atau -0,9945 < 0,220 dan data diberi perlakuan Lhitung<Ltabel atau -0,8264 < 0,220 menunjukan bahwa kelompok data berdistribusi normal.Uji hipotesis dengan menggunakan uji-t pada taraf nyata α = 0,05 diperoleh Thitung = 3,83 dan karena dk=14, maka Ttabel = 1,7531. Maka Thitung = 3,83 >Ttabel 1,7531 . Berdasarkan hasil penelitian tersebut dapat disimpulkan ada pengaruh yang signifikan dari bermain lempar tangkap bola terhadap keterampilan motorik kasar anak usia 5-6 tahun di TK melbourn.Kata Kunci: Keterampilan motorik, Permainan, Lempar tangkap bola, Anak usia 5-6 tahun.