The “Boston” school-choice mechanism: an axiomatic approach

Kojima, Fuhito,Ü,nver, M. Utku Springer-Verlag 2014 Economic theory Vol.55 No.3

Effect of surface treatments on shear bond strength of resin composite bonded to CAD/CAM resin-ceramic hybrid materials

Merve Bankoğlu Güngör,Seçil Karakoca Nemli,Bilge Turhan Bal,Senem Ünver,Aylin Doğan 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.4

PURPOSE The purpose of this study was to assess the effect of surface treatments on shear bond strength of resin composite bonded to thermocycled and non-thermocycled CAD/CAM resin-ceramic hybrid materials. MATERIALS AND METHODS 120 specimens (10×10×2 mm) from each material were divided into 12 groups according to different surface treatments in combination with thermal aging procedures. Surface treatment methods were airborne-particle abrasion (abraded with 50 micron alumina particles), dry grinding (grinded with 125 µm grain size bur), and hydrofluoric acid (9%) and silane application. According to the thermocycling procedure, the groups were assigned as non-thermocycled, thermocycled after packing composites, and thermocycled before packing composites. The average surface roughness of the non-thermocycled specimens were measured after surface treatments. After packing composites and thermocycling procedures, shear bond strength (SBS) of the specimens were tested. The results of surface roughness were statistically analyzed by 2-way Analysis of Variance (ANOVA), and SBS results were statistically analyzed by 3-way ANOVA. RESULTS Surface roughness of GC were significantly lower than that of LU and VE (P<.05). The highest surface roughness was observed for dry grinding group, followed by airborne particle abraded group (P<.05). Comparing the materials within the same surface treatment method revealed that untreated surfaces generally showed lower SBS values. The values of untreated LU specimens showed significantly different SBS values compared to those of other surface treatment groups (P<.05). CONCLUSION SBS was affected by surface treatments. Thermocycling did not have any effect on the SBS of the materials except acid and silane applied GC specimens, which were subjected to thermocycling before packing of the composite resin.

NGA Transition in Turkey: A Comparative Analysis of LLU and FTTX in An Immature Broadband Market

M. Bilal Ünver,Mehmet Altınsoy 정보통신정책학회 2012 정보통신정책연구 Vol.19 No.2

Turkey is a country with an immature broadband industry. No competitive networks are operative in the broadband market and high-speed access is underdeveloped. The country faces critical regulatory junctures that will have strategic importance for future network growth. Open access regimes such as those of the European countries generally refrain from dictating a specific access model, an approach that is also applied to next-generation networks. In contrast, IP-level bitstream access (BSA) has been the predominant model governing broadband competition in Turkey. As the country is at the crossroads of implementing a framework for next-generation, high-bit rate broadband networks, it faces the question of whether it should imitate the European path by encouraging local loop unbundling (LLU) and other intermediate access policies or whether it should chart a different course that might lead to faster next-generation access (NGA) deployment. To analyse this question, the article reports a quantitative analysis of two possible transition paths from BSA: reliance on copper LLU as an interim step and a more direct and to-the-end route of fibre deployment (FTTX). For each scenario, the pay-back periods and break-even points are calculated. It is concluded that broadband competition requires remedies that facilitate FTTX deployment to tackle the problem of lack of innovation as well as to ensure competitive and faster NGA transition in Turkey. Last but not least, mandatory duct sharing rather than unbundling seems to be the most promising way to sustain and develop NGA competition in Turkey.

Pilates-Based Training for Postural Stability in Patients with Schizophrenia

Emin Ulaş Erdem(Emin Ulaş Erdem ),Eda Akbas(Eda Akbas ),Banu Ünver(Banu Ünver ) 사피엔시아 2019 Exercise Medicine Vol.3 No.-

Objectives: Impairment in postural stability is prevalent in schizophrenia patients and this poses potential hazards. This study was planned to investigate whether the Pilates-based training improve the postural stability of patients with schizophrenia. Methods: Outpatients with schizophrenia were allocated to either Pilates exercise group (n=10), or control group (n=10) receiving no exercise. Pilates exercise group participated in supervised Pilates mat exercise program twice per week for six weeks, while the control group participated in no regular physical activity during study. Biodex Balance System was used to assess the participants’ postural stability at the baseline and after six weeks. Results: Statistical analysis revealed that Pilates exercise group showed significant improvement in terms of overall and medial/lateral postural stability scores in static condition (p<0.05). Also, overall and anterior/posterior index scores on left leg, overall and medial/lateral index scores on right leg decreased after training (p<0.05). Postural stability scores in dynamic condition, medial/lateral index score on left leg and anterior/posterior index score on right leg did not change in the Pilates exercise group (p>0.05). Conclusions: Our results showed that Pilates-based training benefit and suggest potential particular benefits in terms of postural stability in patients with schizophrenia. Pilates exercise can be added to the rehabilitation program of schizophrenia patients as a safe and effective method. Future research should include comparative exercise groups in order to determine any particular advantage to Pilates-based training in schizophrenia.

Cyst Fluid Carcinoembryonic Antigen Level Difference between Mucinous Cystic Neoplasms and Intraductal Papillary Mucinous Neoplasms

Ibrahim Hakkı Köker,Nurcan Ünver,Fatma Ümit Malya,Ömer Uysal,Elmas Biberci Keskin,Hakan Şentürk 대한소화기내시경학회 2021 Clinical Endoscopy Vol.54 No.1

Background/Aims: The role of cyst fluid carcinoembryonic antigen (CEA) level in differentiating mucinous pancreatic cystic lesions(PCLs) is controversial. We investigated the role of cyst fluid CEA in differentiating low-risk (LR)-intraductal papillary mucinousneoplasms (IPMNs) from high-risk (HR)-IPMNs and LR-mucinous cystic neoplasms (MCNs). Methods: This was a retrospective study of 466 patients with PCLs who underwent endoscopic ultrasound-guided fine-needleaspirationover a 7-year period. On histology, low-grade dysplasia and intermediate-grade dysplasia were considered LR, whereashigh-grade dysplasia and invasive carcinoma were considered HR. Results: Data on cyst fluid CEA levels were available for 50/102 mucinous PCLs with definitive diagnoses. The median CEA (range)levels were significantly higher in HR cysts than in LR cysts (2,624 [0.5–266,510] ng/mL vs. 100 [16.8–53,445] ng/mL, p=0.0012). The area under the receiver operating characteristic curve (AUROC) was 0.930 (95% confidence interval [CI], 0.5–0.8; p<0.001) fordifferentiating LR-IPMNs from LR-MCNs. The AUROC was 0.921 (95% CI, 0.823–1.000; p<0.001) for differentiating LR-IPMNsfrom HR-IPMNs. Both had a CEA cutoff level of >100 ng/mL, with a negative predictive value (NPV) of 100%. Conclusions: Cyst fluid CEA levels significantly vary between LR-IPMNs, LR-MCNs, and HR-IPMNs. A CEA cutoff level of>100 ng/mL had a 100% NPV in differentiating LR-IPMNs from LR-MCNs and HR-IPMNs.

Modeling and analysis of surface roughness of microchannels produced by µ-WEDM using an ANN and Taguchi method

Rahim Jafari,Müge Kahya,Samad Nadimi Bavil Oliaei,Hakkı Özgür Ünver,Tuba Okutucu Özyurt 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

Microchannel heat exchangers are used to remove the high heat fluxes generated in compact electronic devices. The roughness of the microchannels has a significant effect on the heat transfer characteristics, especially the nucleate boiling and pumping power. Therefore, development of predictive models of surface texture is of significant importance in controlling heat transfer characteristics of these devices. In this study, micro-Wire electrical discharge machining (µ-WEDM) was employed to fabricate metal-based microchannel heat sinks with different surface textures. First, experiments were conducted to achieve the desired surface roughness values. Oxygen-free copper is a common material in the cooling systems of electronic devices because of its high thermal conductivity and low cost. Design of experiment approach based on the Taguchi technique was used to find the optimum set of process parameters. An analysis of variance is also performed to determine the significance of process parameters on the surface texture. An artificial neural network model is utilized to assess the variation of the surface roughness with process parameters. The predictions are in very good agreement with results yielding a coefficient of determination of 99.5 %. The results enable to determine µ-WEDM parameters which can result in the desired surface roughness, to have a well-controlled flow and heat transfer characteristics for the microchannels.

Examining Knowledge, Skill, Stress, Satisfaction, and Self-Confidence Levels of Nursing Students in Three Different Simulation Modalities

Üzen Cura Şengül,Kocatepe Vildan,Yıldırım Dilek,Küçükakgün Hilalnur,Atay Selma,Ünver Vesile 한국간호과학회 2020 Asian Nursing Research Vol.14 No.3

Purpose: The aim of this study was to compare the effect of different simulation modalities on knowledge, skill, stress, satisfaction, and self-confidence levels of students receiving undergraduate education in three nursing schools. Method: This was an experimental study. Students applied the scenario of “Respiratory Sounds Assessment” which was prepared according to three different simulation modalities. In the study, the standardized patient, high-fidelity simulation, and partial task trainer were used as simulation modalities. Results: An increase was observed in postpractice knowledge levels of the three groups which had similar knowledge levels before the practice. Virtual Analog Scale stress levels of the students in the standardized patient group were higher than those of others. The students’ mean scores of satisfaction in learning were higher in the standardized patient group. The students in the partial task trainer group had lower scores of self-confidence in learning. Skill scores of the students were lower in the standardized patient practice than those in others. Conclusion: Simulation-based experiences give students the opportunity of experiencing situations they may experience in the actual practice beforehand. Therefore, this may increase their performance in real practices, as reality increases in the standardized patient group.