Modeling and Optimization of Chemical Mechanical Planarization (Cmp) Using Neural Networks, Anfis and Evolutionary Algorithms

Higher density nano-devices and more metallization layers in microelectronic chips are unceasing goals to the present semiconductor industry. However, topological imperfections (higher non-uniformity) on the wafer surfaces and lower material removal rates (MRR) seriously hamper these pursuing motivations. Since'90, industry has been using chemical mechanical planarization/polishing (CMP) to overcome these obstacles for fabricating integrated circuits (IC) with interconnect geometries of < 0.18 &amp;#956;m. Obviously, the much needed understanding of this new technique is derived basically on the ancient lapping process. Modeling and simulation are critical to transfer CMP from an engineering 'art' to an engineering 'science'. Many efforts in CMP modeling have been made in the last decade, but the available analytical MRR and surface uniformity models cannot precisely describe this highly complicated process, involving simultaneous chemical reactions (and etching), and mechanical abrasion. In this investigation, neural networks (NN), adaptive-based-network fuzzy inference system (ANFIS), and evolutionary algorithms (EA) techniques were applied to successfully overcome the aforementioned modeling and simulation problems. In addition, fine-tuning techniques for re-modifying ANFIS models for sparse-data case using are developed. Furthermore, multi-objective evolutionary algorithms (MOEA) are firstly applied to search for the optimal input settings for CMP process to trade-off the higher MRR and lower non-Uniformity by using the previously constructed models. The results also show the simulation of MOEA optimization can certainly provide accurate guidance to search the optimal input settings for CMP process to produce lower non-uniform wafer surfaces under higher MRR.Mechanical & Aerospace Engineerin

Delivery Route Management based on Dijkstra Algorithm

بالنسبة للشركات التي تقدم خدمات التوصيل، فإن كفاءة عملية التسليم من حيث الالتزام بالمواعيد مهمة للغاية. بالإضافة إلى زيادة ثقة العملاء ، فإن الإدارة الفعالة للمسار والاختيار مطلوبة لتقليل تكاليف وقود السيارة وتسريع التسليم. لا تزال بعض الشركات الصغيرة والمتوسطة تستخدم الأساليب التقليدية لإدارة طرق التسليم. لا تستخدم قرارات إدارة جداول التسليم والمسارات أي طرق محددة لتسريع عملية تسوية التسليم. هذه العملية غير فعالة وتستغرق وقتًا طويلاً وتزيد التكاليف وتكون عرضة للأخطاء. لذلك ، تم استخدام خوارزمية Dijkstra لتحسين عملية إدارة التسليم. تم تطوير نظام إدارة التسليم لمساعدة المديرين والسائقين على جدولة طرق فعالة لتسليم طلبات المنتجات إلى المستلمين. بناءً على الاختبار ، عملت خوارزمية Dijkstra التي تم تضمينها في أقرب وظيفة بحث عن المسار لعملية التسليم بشكل جيد. من المتوقع أن يؤدي هذا النظام إلى تحسين الإدارة الفعالة وتسليم الطلبات.For businesses that provide delivery services, the efficiency of the delivery process in terms of punctuality is very important. In addition to increasing customer trust, efficient route management, and selection are required to reduce vehicle fuel costs and expedite delivery. Some small and medium businesses still use conventional methods to manage delivery routes. Decisions to manage delivery schedules and routes do not use any specific methods to expedite the delivery settlement process. This process is inefficient, takes a long time, increases costs and is prone to errors. Therefore, the Dijkstra algorithm has been used to improve the delivery management process. A delivery management system was developed to help managers and drivers schedule efficient ways to deliver product orders to recipients. Based on testing, the Dijkstra algorithm that has been included in the nearest route search function for the delivery process has worked well. This system is expected to improve the efficient management and delivery of orders

WHAT DETERMINATES STUDENT LEARNING SATISFACTION IN A BLENDED E-LEARNING SYSTEM ENVIRONMENT?

This paper presents a learning satisfaction model that examines the determinant factors for student learning satisfaction in a blended e-learning environment. Conformation factor analysis was performed to test the reliability and validity of the measurement model. The partial least squares method was used to evaluate the causal model. The results indicated that the learning climate, perceived value and perceived ease of use significantly affected learning satisfaction. Computer self-efficacy had a strong impact on perceived behavioral control; computer self-efficacy, perceived behavioral control and social interaction had significant effects on perceived ease of use. System functionality, content feature and social interaction significantly affected perceived value. Social interaction had a significant effect on learning climate. This paper provides initial insights into those factors that are likely significant antecedents for planning and implementing a blended e-learning system to enhance student learning satisfaction

Management of Anaphylactic Shock During Intravenous Fluorescein Angiography at an Outpatient Clinic

We report the proper management of a severe adverse reaction of anaphylactic shock during intravenous fluorescein angiography at an outpatient clinic. A 72-year-old male developed the severe, life-threatening complication after intravenous injection of sodium fluorescein dye for retinal angiography. Three minutes after receiving an intravenous injection of fluorescein, the patient developed syncope, apnea and circulatory shock. Fortunately, he recovered without any neurologic sequelae after immediate intensive resuscitation with fluid and inotropic support. We highlight the occurrence of anaphylactic shock as a potentially fatal complication during intravenous fluorescein angiography. Thus, one should be alert to the possibility of this adverse event and be prepared to deal with it when fluorescein angiography is performed. When it happens, immediate intensive medical resuscitation is essential to minimize morbidity and to avoid mortality

THE LONG -TERM VARIATION OF ORGANIC CHARACTERISTICS IN DONGGANG RIVER USING EXCITATION EMISSION FLUORESCENT MATRIX (EEFM) INTEGRATED WITH PARALLEL FACTOR ANALYSIS (PARAFAC)

In this study, Excitation Emission Fluorescent matrix (EEFM) integrated with Parallel factor analysis (PARAFAC) was applied to investigate the variation of organic property in Donggang River located in Southern Taiwan between Oct. 2010 and Oct. 2015. It reveals that both values of BOD5and COD had a closer proximity at twice samplings; however, the four main components in both samplings showed a different location of excitation and emission wavelengths. On Oct., 2010, EX/EM (percentage of area) of four components were respectively 320/410 nm (46 %), 370/460 nm (27 %), 290/350 nm (14 %) and 280/450 nm (13 %) mainly belonging to humic-like substance. Regrading to the result on Oct, 2015, 320/420 nm (29 %), 228,278/358 nm (29 %), 240/420(29 %) nm and 228/310 nm (14 %) were found attributed in amino organic substance with low excitation wavelength. On Oct.2015, the intensities of four main components in Cinsheda Bridge higher than those in other locations may be attributed with of heavily polluted source like piggery wastewater. For the partition of N-organic and C-organic, there had a significant change on both samplings

Trends in Seaweed Research

This is a letter on the evolution of trends in seaweed research with respect to the development of technology and generation of knowledge, as well as difficulties and future perspectives in seaweed research

Anti-Oxidative Abilities of Essential Oils from Atractylodes ovata Rhizome

The rhizome of Atractylodes ovata De Candolle is rich in essential oils, which are usually removed by processing. In this study, anti-oxidative abilities of essential oils and aqueous extracts of A. ovata rhizome were explored, and the influence of processing on the anti-oxidative abilities was examined. Essential oils and aqueous extracts of A. ovata were extracted by boiling water and steam distillation, respectively. Quality of these two A. ovata samples was controlled by HPLC and GC-MS system, and anti-oxidative abilities were then evaluated. Results showed that surface color of A. ovata turned to brown and chemical components were changed by processing. Contents of both atractylon and atractylenolide II decreased in the essential oils, but only the contents of atractylon decreased by processing. Atractylenolide III increased in both A. ovata samples. However, A. ovata essential oils displayed stronger anti-oxidative abilities than aqueous extracts in DPPH-scavenging, TBH-induced lipid peroxidation and catalase activity assays. Moreover, the bioactivity of essential oils from raw A. ovata was stronger than oils from processed A. ovata. On the other hand, cytotoxicity of A. ovata essential oils was stronger than that of aqueous extracts, and was more sensitive on H9C2 cell than NIH-3T3 and WI-38 cells. In contrast, stir-frying processing method increased cytotoxicity of essential oils, but the cytotoxicity was ameliorated when processed with assistant substances. The results suggested that phytochemical components and bioactivity of A. ovata were changed after processing and the essential oils from raw A. ovata showed better anti-oxidative and fewer cytotoxicity effects

Biomechanical comparison of lumbar spine instability between laminectomy and bilateral laminotomy for spinal stenosis syndrome – an experimental study in porcine model

<p>Abstract</p> <p>Background</p> <p>The association of lumbar spine instability between laminectomy and laminotomy has been clinically studied, but the corresponding <it>in vitro </it>biomechanical studies have not been reported. We investigated the hypothesis that the integrity of the posterior complex (spinous process-interspinous ligament-spinous process) plays an important role on the postoperative spinal stability in decompressive surgery.</p> <p>Methods</p> <p>Eight porcine lumbar spine specimens were studied. Each specimen was tested intact and after two decompression procedures. All posterior components were preserved in Group A (Intact). In Group B (Bilateral laminotomy), the inferior margin of L4 lamina and superior margin of L5 lamina were removed, but the L4–L5 supraspinous ligament was preserved. Fenestrations were made on both sides. In Group C (Laminectomy) the lamina and spinous processes of lower L4 and upper L5 were removed. Ligamentum flavum and supraspinous ligament of L4–L5 were removed. A hydraulic testing machine was used to generate an increasing moment up to 8400 N-mm in flexion and extension. Intervertebral displacement at decompressive level L4–L5 was measured by extensometer</p> <p>Results</p> <p>The results indicated that, under extension motion, intervertebral displacement between the specimen in intact form and at two different decompression levels did not significantly differ (<it>P </it>> 0.05). However, under flexion motion, intervertebral displacement of the laminectomy specimens at decompression level L4–L5 was statistically greater than in intact or bilateral laminotomy specimens (<it>P </it>= 0.0000963 and <it>P </it>= 0.000418, respectively). No difference was found between intact and bilateral laminotomy groups. (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>We concluded that a lumbar spine with posterior complex integrity is less likely to develop segment instability than a lumbar spine with a destroyed anchoring point for supraspinous ligament.</p

Hypothermic manipulation of bone cement can extend the handling time during vertebroplasty

BACKGROUND: Polymethylmethacrylate (PMMA) is commonly used for clinical applications. However, the short handling time increases the probability of a surgeon missing the crucial period in which the cement maintains its ideal viscosity for a successful injection. The aim of this article was to illustrate the effects a reduction in temperature would have on the cement handling time during percutaneous vertebroplasty. METHODS: The injectability of bone cement was assessed using a cement compressor. By twisting the compressor, the piston transmits its axial load to the plunger, which then pumps the bone cement out. The experiments were categorized based on the different types of hypothermic manipulation that were used. In group I (room temperature, sham group), the syringes were kept at 22°C after mixing the bone cement. In group 2 (precooling the bone cement and the container), the PMMA powder and liquid, as well as the beaker, spatula, and syringe, were stored in the refrigerator (4°C) overnight before mixing. In group 3 (ice bath cooling), the syringes were immediately submerged in ice water after mixing the bone cement at room temperature. RESULTS: The average liquid time, paste time, and handling time were 5.1 ± 0.7, 3.4 ± 0.3, and 8.5 ± 0.8 min, respectively, for group 1; 9.4 ± 1.1, 5.8 ± 0.5, and 15.2 ± 1.2 min, respectively, for group 2; and 83.8 ± 5.2, 28.8 ± 6.9, and 112.5 ± 11.3 min, respectively, for group 3. The liquid and paste times could be increased through different cooling methods. In addition, the liquid time (i.e. waiting time) for ice bath cooling was longer than for that of the precooling method (p < 0.05). CONCLUSIONS: Both precooling (i.e. lowering the initial temperature) and ice bath cooling (i.e. lowering the surrounding temperature) can effectively slow polymerization. Precooling is easy for clinical applications, while ice bath cooling might be more suitable for multiple-level vertebroplasty. Clinicians can take advantage of the improved injectability without any increased cost