检索结果-南通市图书馆

Chinese Physics Letters 2013年第1期30卷 165-168页

作者： ahmet Kaya Şemsettin Altındal YaseminŞafak Asar Zekayi Sönmez Department of Physics Faculty of SciencesGazi University06500AnkaraTurkey

An Al/SiO_(2)/p-Si(MOS)capacitor with a thick(826Å)interfacial oxide layer(SiO_(2))which is formed by using the thermal oxidation method is fabricated to investigate both frequency and applied bias voltage dependences of real and imaginary parts of dielectric constant(ϵ'andϵ")and electric modulus(M'and M"),loss tangent(tanδ)and ac electrical conductivity(σ_(ac))in a wide frequency range from 1 kHz to 1 MHz at room *** dielectric properties of the MOS capacitor are obtained using the forward and reverse bias capacitance-voltage(C–V)and conductance-voltage(G/ω–V)measurements in the applied bias voltage range 1.4–5.6 *** values ofϵ',ϵ",tanδ,M',M"and σ_(ac) are found to be strong functions of frequency and applied bias voltage in the depletion region due to excess capacitance Cex and conductance G_(ex)/ω especially at low *** experimental results show that the interfacial polarization can occur at low frequencies more easily,consequently contributing to the dispersion inϵ',ϵ",tanδ,M',M"and σ_(ac) values of the MOS *** other reason for dispersion in the dielectric properties may be attributed to a particular density distribution of interface states(Nss)localized at the Si/SiO_(2) interface,as well as space charge carriers and inhomogeneity of interfacial oxide *** increase in conductivity with increasing frequency can be attributed to the hopping type conduction *** can be concluded that theϵ',ϵ",tanδ,M',M"and σ_(ac) values of the Al/SiO_(2)/p-Si(MOS)capacitor are strongly dependent on both the frequency and applied bias voltage especially in the depletion region.

关键词： polarization dielectric interfacial

Decision making on financial investment in Turkey by using ARDL long-term coefficients and AHP

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Financial Innovation 2020年第1期6卷 530-551页

作者： Serkan Atmaca Hacıahmet Karadaş Department of Mathematics Faculty of ScienceSivas Cumhuriyet UniversitySivasTurkey Department of Economics Faculty of Economics and Administrative SciencesSivas Cumhuriyet University SivasTurkey

Mathematical modeling methods are frequently used for solving everyday *** making,one such method,can be used in every aspect of life for different scales such as micro(households),medium(companies),and macro(states)*** to the large number of parameters affecting decision,it is possible to make mistakes in the selection of the appropriate investment instrument with classical methods;hence,scarce resources may be wasted,and sometimes it may even be impossible to make a *** study seeks to answer the question“Which financial investment instrument should be selected under the current conditions?”using decision making *** affecting gold,USD,and EURO,which are selected as the financial investment instruments in Turkey,are examined using the autoregressive distributed lag(ARDL)bound *** selected variables are monthly and belong to the January 2009 to May 2018 *** ARDL results show that the selected financial investment instruments are affected by most of the factors *** using the coefficients obtained from the ARDL model,the analytic hierarchy process(AHP)model was *** to the results of the model,the EURO was determined as the most suitable financial investment for ahmet and others with the same preferences.

关键词： Decision making Financial investment instruments ARDL AHP

Forecasting cyberattacks with incomplete,imbalanced,and insignificant data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cybersecurity 2018年第1期1卷 263-278页

作者： ahmet Okutan Gordon Werner Shanchieh Jay Yang Katie McConky Computer Engineering Rochester Institute of TechnologyRochesterNYUSA Industrial&Systems Engineering Rochester Institute of TechnologyRochesterNYUSA

Having the ability to forecast cyberattacks before they happen will unquestionably change the landscape of cyber warfare and cyber *** work predicts specific types of attacks on a potential victim network before the actual malicious actions take *** challenge to forecasting cyberattacks is to extract relevant and reliable signals to treat sporadic and seemingly random acts of *** paper builds on multi-faceted machine learning solutions and develops an integrated system to transform large volumes of public data to aggregate signals with imputation that are relevant and predictive of cyber incidents.A comprehensive analysis of the individual parts and the integrated whole demonstrates the effectiveness and trade-offs of the proposed *** 16-months of reported cyber incidents by an anonymized victim organization,the integrated approach achieves up to 87%,90%,and 96% AUC for forecasting endpoint-malware,malicious-destination,and malicious-email attacks,*** assessed month-by-month,the proposed approach shows robustness to perform consistently well,achieving F-Measure between 0.6 and *** framework also enables an examination of which unconventional signals are meaningful for cyberattack forecasting.

关键词： Cyber security Forecasting Unconventional signals

Measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2013年第4期6卷 521-525页

作者： ahmet Taylan Yazici Gkhan Pekel Ercüment Bozkurt Yusuf Yildirim Evre Pekel ahmet Demirok mer Faruk Yilmaz Beyoglu Eye Training and Research Hospital Department of Ophthalmology Pamukkale University

AIM:To evaluate the measurements of anterior segment parameters using three different non-contact optical devices in keratoconus patients.·METHODS:A hundred and one eyes of 55 keratoconus patients were enrolled in this *** mean age was26.2 ±8.9 *** inclusion criteria were keratoconus stage I to III according to the Amsler-Krumeich keratoconus *** the measurements were done by the same operator,under the mesopic light condition and repeated with three different optical methods;Visante,Orbscan and *** evaluated anterior segment parameters were anterior chamber depth(ACD),central and thinnest corneal thickness(CCT and TCT) and pupil diameter(PD).·RESULTS:The mean CCT measured by Visante,Orbscan and Pentacam were as follows:462.0 ±48.1μm,463.9±60.9μm,476.5±45.3μm,respectively(P =0.873).The mean ACD values were 3.34±0.33mm,3.26±0.33mm,3.49±0.40mm,respectively(P=0.118).The mean PD measurements were 5.11 ±1.14mm,4.80 ±0.85mm,3.80 ±1.38mm,respectively(P <0.001).The mean TCT measurements of Visante,Orbscan and Pentacam were 437.9 ±48.2μm,447.6±60.6μm and 459.9±44.0μm,respectively(P =0.214).The Visante and Orbscan measured CCT similarly,while Pentacam measured CCT thicker than the other *** Visante measured TCT thinner than the other two *** ACD measurements,Orbscan was the one giving the lowest *** was measured differently by the devices.·CONCLUSION:Although TCT,CCT and ACD measurements acquired by Visante,Orbscan and Pentacam in keratoconus patients are similar,PDmeasurements show large differences among the devices.

关键词： Visante Orbscan Pentacam corneal pachymetry anterior chamber depth pupil diameter

Comparison of satellite images with different spatial resolutions to estimate stand structural diversity in urban forests

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Forestry Research 2017年第4期28卷 805-814页

作者： Ulas Yunus Ozkan Ibrahim Ozdemir Tufan Demirel Serhun Saglam ahmet Yesil Department of Forest Management Faculty of ForestryIstanbul University Wildlife Ecology and Management Faculty of ForestrySuleyman Demirel University

The structural diversity in urban forests is highly important to protect biodiversity. In particular, fruit trees and bush species, cavity-bearing trees and coarse, woody debris provide habitats for animals to feed, nest and hide. Improper silvicultural practices, intensive recreational use and illegal harvesting lead to a decline in the structural diversity in forests within larger metropolitan cities. It is important to monitor the structural diversity at definite time intervals using effective technologies with a view to instituting the necessary conservation measures. The use of satellite images seems to be appropriate to this end. Here we aimed to identify the associations between the textural features derived from the satellite images with different spatial resolutions and the structural diversity indices in urban forest stands (Shannon-Wiener index, complexity index, dominance index and density of wildlife trees). RapidEye images with a spatial resolution of 5 m × 5 m, ASTER images with a spatial resolution of 15 m × 15 m and Landsat-8 ETM satellite images with a spatial resolution of 30 m × 30 m were used in this study. The first-order (standard deviation of gray levels) and second order (GLCM entropy, GLCM contrast and GLCM correlation) textural features were calculated from the satellite images. When associations between textural features in the images and the structural diversity indices were assessed using the Pearson correlation coefficient, very high associations were found between the image textural features and the diversity indices. The highest association was found between the standard deviation of gray levels (SDGLRAP) derived from RVIRAP of RapidEye image and the Shannon-Wiener index (H h) calculated on the basis of tree height (R 2 = 0.64). The findings revealed that RapidEye satellite images with a spatial resolution of 5 m × 5 m are most suitable for estimating the structural diversity in urban fores

关键词： Biodiversity Satellite image Structural diversity Texture measures Urban forests

The removal of Cr(Ⅵ) through polymeric supported liquid membrane by using calix[4]arene as a carrier

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2019年第1期27卷 85-91页

作者： Canan Onac ahmet Kaya Duygu Ataman Nefise Ayhan Gunduz H.Korkmaz Alpoguz Department of Chemistry Pamukkale University

In this work, the transport and removal of Cr(Ⅵ) were achieved through supported liquid membrane(SLM) by using a 5,17, di-tert-butyl-11,23-bis[(1,4-dioxa-8-azaspiro [4,5]decanyl)methyl]-25,26,27,28-tetrahydroxy calix[4]arene carrier, dissolved in 2-nitrophenyl octyl ether *** studied parameters are the solvent effect in the membrane phase, the effect of carrier concentration, and the acid type in the donor *** Celgard 2500 was used as a membrane *** used the Danesi mass transfer model to calculate the permeability coefficients for each studied *** addition, AFM and SEM techniques were used to characterize the surface morphology of the prepared Celgard 2500 membrane that included the calix[4]arene carrier.

关键词： Resorcinarene Liquid membrane Cr(Ⅵ) Surface characterization

Ma’s Variation of Parameters Method for Fisher’s Equations

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2010年第3期2卷 379-388页

作者： Syed Tauseef Mohyud-Din ahmet Yıldırım HITEC University Taxila Cantt Pakistan Ege University Department of Mathematics35100 Bornova-IzmirTurkey

In this paper,we apply Ma’s variation of parameters method(VPM)for solving Fisher’s *** suggested algorithm proved to be very efficient and finds the solution without any discretization,linearization,perturbation or... 详细信息

关键词： Variation of parameters method variational iteration method nonlinear problems Fisher’s equation nonlinear diffusion equation error estimates

Effect of long-term Helicobacter pylori infection on growth of children:a cohort study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

世界儿科杂志:英文版 2016年第2期12卷 196-201页

作者： Celebi Kocaoglu ahmet Ozel Mustafa Cayci Ece Selma Solak Department of Pediatrics Konya Education and Research Hospital42090 MeramKonyaTurkey Department of Pediatric Nephrology Konya Education and Research Hospital42090 MeramKonyaTurkey Department of Nuclear Medicine Konya Education and Research Hospital42090 MeramKonyaTurkey

Background:The effects of Helicobacter pylori(***)infection on growth are a controversial *** investigated the effects of long-term *** infection on height and weight in ***:A total of 200 children of 7-18 years old suffering from dyspeptic complaints were classified into two groups:*** positive and negative groups,*** the infection was impoved was followed up while performing urea breath test,and according to exposure time to the infection,the children were further divided into group 1(≤1.5 months),group 2(>1.5-≤6 months)and group 3(>6 months).Antropometric measurements were obtained and repeated every six ***:Mean growth velocity scores in the *** positive and negative groups were 0.49±3.85[95%confidence interval(CI):-0.21-1.18]and 1.98±4.42(95%CI:1-2.96),*** difference between both groups was statistically significant(P=0.012).Mean growth velocity scores in groups 1,2 and 3 were 0.96±3.84,0.16±4.51 and-0.85±3.09,*** growth velocity scores of group 3 were significantly lower than those of groups 0 and 1(P=0.005 and P=0.041).The mean weight scores in group 3 were similar to those in group 2,but the scores in group 3 were signifi cantly lower than those in group 1(-1.75±1.05,-1.21±1.37 and-0.88±1.49,respectively).Conclusion:As the duration of exposure is prolonged in children with *** infection,the negative effect of the infection on both height and weight is evident.

关键词： antropometry failure to thrive growth velocity Helicobacter pylori

Demographic features and histopathological diagnosis in primary eyelid tumors: results over 19 years from a tertiary center in Ankara, Turkey

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2020年第8期13卷 1287-1293页

作者： Mehtap Arslantürk Eren ahmet Kaan Gündüz Department of Ophthalmology Ankara University Faculty of MedicineAnkara 06620Turkey

AIM:To evaluate the demographic features,location,and histopathologic results in primary eyelid ***:We retrospectively reviewed the records of patients with primary eyelid tumor diagnosed and treated between November 1997 and June 2016 on our ***:Nine hundred and eleven lesions from 874 patients were included in this *** hundred and fortysix(51.0%)of the patients were females and 428(49.0%)were *** mean age was 51.0y(range:3 mo-94 y).The lesions were located in the upper eyelid(418 cases,45.9%),lower eyelid(378 cases,41.5%),medial canthus(89 cases,9.8%),and lateral canthus(26 cases,2.8%).Four hundred and seventy(51.6%)lesions were located on the right side and 441(48.4%)on the *** the eyelid lesions,666(73.1%)were benign,230(25.2%)malignant,and 15(1.6%)*** the eyelid tumors were classified according to their tissue or cell of origin,527(57.8%)of the lesions were found to be epidermal,171(18.8%)adnexal,131(14.4%)inflammatory and infectious,and 65(7.1%)*** most common benign lesions were squamous cell papilloma(139 lesions,15.2%),intradermal nevus(97 lesions,10.6%),epidermoid inclusion cysts(78 lesions,8.6%),seborrheic keratosis(60 lesions,6.6%),and inflammatory masses(59 lesions,6.5%).Basal cell carcinoma was the most common malignant tumor(191 lesions,21.0%)followed by squamous cell carcinoma(16 lesions,1.8%),sebaceous carcinoma(14 lesions,1.5%),and malignant melanoma(5 lesions,0.5%).CONCLUSION:In this study,73.1%of eyelid lesions are benign and the remaining 26.9%are premalignant and *** cell carcinoma is the most common tumor among all histopathological diagnosis followed by squamous papilloma.

关键词： eyelid tumors histopathology basal cell carcinoma squamous papilloma

Splenogonadal fusion-limb deformity syndrome: a rare but important cause of undescended testis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

世界儿科杂志:英文版 2016年第2期12卷 246-248页

作者： ahmet Celik Sibel Tiryaki Sukran Darcan Orkan Ergun Department of Pediatric Surgery Ege University Faculty of MedicineIzmirTurkey Department of Pediatrics Division of Pediatric EndocrinologyEge University Faculty of MedicineIzmirTurkey

Background: Splenogonadal fusion is a rare congenitalanomaly which is characterized by fusion formationbetween the spleen and ***: We report a case of a 14-month boy withspleongonadal fusion-limb deformity syndrome focusingon the importance of awareness of this ***: The patient was admitted to our clinic becauseof a left undescended testis, and preoperative diagnosiswas not made. During the operation, "spleen-like" tissueattached to the gonad induced splenogonadal fusion, whichwas confi rmed by laparoscopy. The patient also had a shortright femur, hip dysplasia and a syndromic ***: Splenogonadal fusion anomaly shouldbe considered in the evaluation of undescended testis,especially in patients with facial and limb deformities.

关键词： diagnostic laparoscopy splenogonadal fusion undescended testis