1,141 research outputs found
Where Does the Density Localize? Convergent Behavior for Global Hybrids, Range Separation, and DFT+U
Approximate density functional theory (DFT) suffers from many-electron self-
interaction error, otherwise known as delocalization error, that may be
diagnosed and then corrected through elimination of the deviation from exact
piecewise linear behavior between integer electron numbers. Although paths to
correction of energetic delocalization error are well- established, the impact
of these corrections on the electron density is less well-studied. Here, we
compare the effect on density delocalization of DFT+U, global hybrid tuning,
and range- separated hybrid tuning on a diverse test set of 32 transition metal
complexes and observe the three methods to have qualitatively equivalent
effects on the ground state density. Regardless of valence orbital diffuseness
(i.e., from 2p to 5p), ligand electronegativity (i.e., from Al to O), basis set
(i.e., plane wave versus localized basis set), metal (i.e., Ti, Fe, Ni) and
spin state, or tuning method, we consistently observe substantial charge loss
at the metal and gain at ligand atoms (ca. 0.3-0.5 e or more). This charge loss
at the metal is preferentially from the minority spin, leading to increasing
magnetic moment as well. Using accurate wavefunction theory references, we
observe that a minimum error in partial charges and magnetic moments occur at
higher tuning parameters than typically employed to eliminate energetic
delocalization error. These observations motivate the need to develop
multi-faceted approximate-DFT error correction approaches that separately treat
density delocalization and energetic errors in order to recover both correct
density and magnetization properties.Comment: 34 pages, 11 figure
Dam Rain and Cumulative Gain
We consider a financial contract that delivers a single cash flow given by
the terminal value of a cumulative gains process. The problem of modelling and
pricing such an asset and associated derivatives is important, for example, in
the determination of optimal insurance claims reserve policies, and in the
pricing of reinsurance contracts. In the insurance setting, the aggregate
claims play the role of the cumulative gains, and the terminal cash flow
represents the totality of the claims payable for the given accounting period.
A similar example arises when we consider the accumulation of losses in a
credit portfolio, and value a contract that pays an amount equal to the
totality of the losses over a given time interval. An explicit expression for
the value process is obtained. The price of an Arrow-Debreu security on the
cumulative gains process is determined, and is used to obtain a closed-form
expression for the price of a European-style option on the value of the asset.
The results obtained make use of various remarkable properties of the gamma
bridge process, and are applicable to a wide variety of financial products
based on cumulative gains processes such as aggregate claims, credit portfolio
losses, defined-benefit pension schemes, emissions, and rainfall.Comment: 25 Pages, 1 Figur
Pengaruh Hambatan Komunikasi Terhadap Kinerja Karyawan Hotel Midtown Surabaya
Penelitian ini dilakukan untuk mengetahui pengaruh hambatan komunikasi terhadap kinerja karyawan di Hotel Midtown Surabaya. Komunikasi organisasi yang efektif dibutuhkan dalam organisasi tersebut. Dalam komunikasi tersebut disinyalir adanya hambatan komunikasi di divisi Sales & Marketing, Finance & Accounting, Rooms dan Food & Beverage Marketing. Peneliti menggunakan teori komunikasi organisasi, hambatan komunikasi dan kinerja karyawan. Elemen-elemen hambatan komunikasi terdiri dari hambatan teknis, semantik dan perilaku mempengaruhi quantity of work, quality of work dan job knowledge karyawan. Jenis penelitian ini adalah eksplanatif dengan pendekatan kuantitatif. Metode penelitian yang digunakan adalah survei dengan penerapan skala Likert. Sampel dalam penelitian ini adalah seluruh karyawan Hotel Midtown Surabaya yang berjumlah 101 orang. Hasil dari penelitian ini menunjukkan hambatan komunikasi mempengaruhi kinerja karyawan Hotel Midtown Surabaya
A Review of Hearing Loss in Cleft Palate Patients
Background. Cleft palate is associated with recurrent otitis media with effusion and hearing loss. This study analysed the way these patients' hearing is managed in Alder Hey Children's Hospital. Method. A retrospective audit was carried out on cleft palate patients in Alder Hey Children's Hospital. Audiology assessment and treatment options were reviewed. Comparisons were made between the use of ventilation tubes (VTs) and hearing aids (HAs). The types of cleft, types of hearing loss, and the management output of the audiology regions were also reviewed. Results. The audiology assessments of 254 patients were examined. The incidence of VT insertion in this group of patients was 18.9%. The hearing aid incidence rate was 10.1%. The VT-related complication rate was 25.5% and the HA related complication rate was 9.1%. Conclusion. The data demonstrates that both treatments are viable, and a new protocol which combines the short term benefit of VT insertion with the lower complication rate of HA is required
Laparoscopic drainage of an intramural duodenal haematoma: a novel technique and review of the literature
Intramural Duodenal Haematoma (IDH) is an uncommon complication of blunt abdominal trauma. IDH's are most often treated non-operatively. We describe laparoscopic treatment of an IDH after failed conservative management. To our knowledge, successful laparoscopic drainage of an IDH in an adult has not been described previously in the literature
AN ALGORITHM FOR SOLVING INTUITIONISTIC FUZZY LINEAR BOTTLENECK ASSIGNMENT PROBLEMS
The linear bottleneck assignment problem (LBAP), which is a variation of the classical assignment problem, seeks to minimize the longest completion time rather than the sum of the completion times when a number of jobs are to be assigned to the same number of workers. If the completion times are not certain, then it is said to be a fuzzy LBAP. Here we propose a new algorithm to solve fuzzy LBAP with completion times as intuitionistic fuzzy numbers
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