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Cost minimization for deploying serverless functions
No full textThe costs of serverless functions increase proportional to the amount of memory reserved on the deployed server. However, increasing the amount of memory decreases the function execution time, which is also a factor that contributes to cost. We propose an automated approach for optimizing the amount of memory reserved for serverless functions. First, we measure the running time of a given function in various memory settings and derive a regression model. Then, we define an objective function and a set of constraints based on this regression model and the configuration space. Finally, we determine the optimal memory setting for minimizing cost. Our industrial case study shows that significant cost reductions can be achieved by accurate estimations of the impact of memory settings on runtime performance
BCPriPIoT: BlockChain utilized privacy-preservation mechanism for IoT devices
No full textSecurity and privacy are the primary concerns for IoT devices but because of their inherent limitation both in terms of processing and energy, IoT devices cannot be deployed at their full scale. To alleviate such security and privacy issues, the interaction of blockchain with IoT systems has acquired significant attention these days because blockchain has presented an underlying mechanism of immutability, audibility, and transparency for data storage. However due to the intrinsic nature of a blockchain containing complex mathematical proof concepts such as Merkle Hash Tree and Proof of Work (PoW) which demands high computation power making it less viable for IoT devices to be connected with. To overcome these issues, a novel scheme is proposed in this paper, which deploys private by design based blockchain architecture for IoT devices using low complex consensus algorithm and low computation cryptographic mechanism which suits best for IoT devices to address the privacy concerns. Unlike the traditional blockchain network in which every node maintained a copy of the transaction, we have proposed a new architecture in which block validation and block generation logic has been modified so that a transaction will be limited to the trusted recipient only. The proposed scheme outperforms the contemporary approaches both in terms of throughput and latency as observed through simulation results as well as maintaining the privacy concerns which will encourage the actual implementation of IoT applications in the real world. Moreover, the evaluation analysis demonstrate that the approach has major potential in a trusted network computing system and provides a substantial secure environment for IoT users
Mapping the scientific research of the life cycle assessment in the construction industry: A scientometric analysis
No full textThe interest toward the life cycle assessment studies in the construction industry has been increasing in the last decades. However, there is no existing study that focuses on mapping the scientific research of the LCAs in the construction industry with a comprehensive understanding. Hence, an expansive and macro level study of the LCAs within the subject domain is necessary to fulfill this gap in the literature. The research objective of this study is to reveal the status quo, hot topics and keywords, and emerging areas of the LCA research in the construction industry. For this purpose, systematic bibliometric and scientometric analyses were conducted by referring 2885 bibliometric records published between 1997 and 2021 (end of February). The analyses indicated China, USA, and Spain as the most productive countries in the field. Additionally, hot keywords in the domain revealed as ‘energy’, ‘environmental impact’, ‘sustainability’, ‘performance’, ‘emission’, ‘building’, ‘system’, ‘design’, and ‘concrete’. ‘Circular economy’, ‘mechanical property’, and ‘footprint’ are found as the emerging areas of this field. Document co-citation clusters showed the hot research themes of the domain as building information modeling (BIM), energy performance, construction and demolition waste, carbonation, water supply, bridge design, optimization, pavement management, ventilation, and design assessment. The results of this research make a significant contribution to the scientific community and industry practitioners by providing an inclusive understanding of the recent status, hot keywords and topics, and emerging areas of the life cycle assessment in the construction industry. Further, this study would be a useful and valuable reference and guideline for the researchers interested in this field
Tank çizelgelemeli ekonomik öbek büyüklüğü belirleme problemi
No full textIn this study, we consider an Economic Lot sizing Problem with Tank Scheduling (ELSTS). The problem is a real-world problem, which is generally found in fermented beverage and food facilities. A facility might produce an item or several different items which have various fermentation times. The facility might have a tank or several identical or non-identical tanks to produce items. If a tank starts the fermen tation process of an item, the tank will not be available to produce any item until its fermentation process is completed. Setup costs when tanks are filled, production costs when tanks are discharged, inventory costs after production is completed are incurred. The aim is to determine the lowest cost tank schedule and production plan which satisfies demands within a given finite planning horizon. Within the scope of the study, we analysed NP-hardness and solution methods of various variants of the ELSTS problem. In addition, for a variant of the ELSTS problem, which is classified as NP-Hard (multiple items that have different fermentation times and multiple iden tical parallel machines), a new heuristic method is proposed to find a near-optimal solution. The proposed heuristic method is compared with a mixed-integer program ming model, and that the heuristic method gives good solutions within seconds is observed.Bu ¸calı¸smada Tank C¸ izelgelemeli Ekonomik Obek B¨uy¨ukl¨u˘g¨u Belirleme problemini ¨ (EOBB-TC¸ ) inceleyece˘giz. Bu problem, ger¸cek hayatta mayalanmı¸s i¸cecek ve gıda ¨ ¨uretimi yapılan fabrikalarda kar¸sıla¸sılan bir problemdir. Bir fabrikada bir veya birden fazla farklı mayalanma s¨uresine sahip ¨ur¨unlerin ¨uretimi ger¸cekle¸stirilebilir. Bu ¨ur¨un veya ¨ur¨unlerin ¨uretiminde bir tank veya birden fazla ¨ozde¸s veya ¨ozde¸s olmayan tanklar kullanılabilir. Bir tank i¸cerisinde bir ¨ur¨un i¸cin mayalanma s¨ureci ba¸slatıldıysa, may alanma i¸slemi ger¸cekle¸sen tank mayalanma s¨ureci tamamlanana kadar hi¸cbir ¨ur¨un¨un ¨uretimi i¸cin kullanılamaz. Bu ¨uretimler sırasında, tanklar doldurulurken kurulum, bo¸saltılırken ¨uretim ve sonrasında envanter tutma maliyetleri olu¸smaktadır. Bu rada ama¸c, belirli ve sınırlı bir planlama ufku i¸cerisinde talepleri kar¸sılayan en d¨u¸s¨uk maliyetli tank ¸cizelgesi ve ¨uretim planını tespit etmektir. Bu ¸calı¸sma kapsamında problemin ¸ce¸sitli varyantlarının NP-zor olma durumları ve ¸c¨oz¨um metodları ¨uzerinde incelemeler yapılmı¸stır. NP-zor sınıfında yer aldı˘gı tespit edilmi¸s bir problem varyantı (farklı mayalanma s¨uresine sahip ¸cok ¨ur¨unl¨u ve ¸cok ¨ozde¸s tanklı) i¸cin sezgisel algo ritmayla yeni bir ¸c¨oz¨um y¨ontemi ¨onerilmi¸stir. Onerilen sezgisel ¸c¨oz¨um algoritmasının ¨ performansı, tamsayı-karı¸sık do˘grusal programlama modeli ile kar¸sıla¸stırılmı¸s ve al goritma kullanılarak saniyeler i¸cerisinde iyi sonu¸clara ula¸sılabildi˘gi g¨ozlemlenmi¸stir
Hafif kompozitlerin birikmeli hadde yapıştırması ile imalatı ve mekanik davranışı
No full textSevere plastic deformation (SPD) methods have received significant attention in fabricating a combination of similar and dissimilar metal composites. Accumulative roll bonding (ARB) is one of the SPD techniques employed to produce high strength, fine-grained, and multi-layered metal matrix composites (MMCs). The current work is characterized into two parts. The major part deals with the fabrication of different combinations between titanium and interstitial free (IF) steel interlayered with aluminum alloy (Al2024). While the second part studies the effect of post-ARB heat treatment on Al2024-IF steel composite. Microstructural evaluation and mechanical characteristics of processed composites were examined by optical microscope (OM), scanning electron microscope (SEM), and mechanical tests. Surface and bulk properties were analyzed through microhardness, uniaxial tensile, and shear punch test (SPT). Finally, experiment results were validated using numerical analysis. For the first case of titanium-IF steel composites, the optical micrographs indicated the reduction in layer thickness and grain size after each rolling cycle. Necking was initiated in some layers of the processed composite after the third (final) ARB cycle, suggesting the interlocking of layers and consequently stronger bonding. SEM figures from fracture surfaces revealed the delamination of layers from interfaces in early cycles, that lessened in the final cycle due to high strain exerted after each rolling cycle. Significant improvement was noticed in hardness levels as the number of ARB cycles increased. Enhancement levels for titanium and IF steel layers were up to 1.4 and 2.6 times, respectively after the ARB process. The tensile strength of the titanium-IF steel composite rolled at 400°C exceeded over 670MPa after three cycles. Typical to SPD processes, the ductility was reduced to less than 5% in all cases after three ARB cycles. Enhancement levels in tensile strength of each layer of the final composite compared to the initial metals were similar to hardness. SPT results showed the improvement in shear strength of the sample with the increasing number of cycles, a maximum shear strength of around 440MPa was achieved after three cycles. For the second part of aluminum-IF steel composite, microstructure observation revealed that long aging imparted partial coarsening of the average grain size in a three-cycle ARBed sample. Furthermore, the ductility was recovered after aging without losing tensile strength due to the occurrence of precipitation hardening along with recovery in individual layers. A maximum ultimate tensile strength (UTS) and ductility of around 420MPa and 18%, respectively, was obtained after aging at 150°C for 24h. SPT results showed a similar response as the tensile test, and maximum shear strength was reached up to 270MPa at the peak-aged condition. The ARB process, in the case of titanium-IF steel composite, was modeled by employing finite element analysis through ANSYS workbench. The effective plastic strain and effective stress (von-Mises) were calculated through the thickness of ARBed samples. A close agreement between experimental findings and numerical simulations was observed.Aşırı plastik deformasyon (APD) yöntemleri, benzer ve farklı metal kompozitlerin üretilmesinde büyük dikkat çekmiştir. Birikmeli hadde yapıştırması (ARB), yüksek mukavemetli, ince iç yapılı ve çok katmanlı metal matrisli kompozitler (MMC) üretmek için kullanılan APD tekniklerinden biridir. Mevcut çalışma iki bölümden oluşmaktadır. Ana kısım, titanyum ve alüminyum alaşımı (Al2024) ile ara tabakalı arayer atomsuz (IF) çelik arasındaki farklı kombinasyonların imalatı üzerinedir. İkinci kısım ise ARB sonrası ısıl işlemin Al2024 ve IF çelik kompozit üzerindeki etkisini inceler. İşlenik kompozitlerin mikroyapı analizleri optik mikroskop (OM) ve taramalı elektron mikroskobu (SEM) ile; mekanik özellikleri ise yapılan mekanik testler ile incelenmiştir. Yüzey ve malzeme özellikleri mikrosertlik, tek eksenli çekme ve kayma zımba testi (SPT) ile analiz edildi. Son olarak, deney sonuçları sayısal analiz yöntemi kullanılarak doğrulanmıştır. Titanyum-IF çelik kompozitlerde, her haddeleme döngüsünden sonra optik mikroskop aracılığı ile tabaka kalınlığında ve tane boyutunda azalma saptandı. İşlenik kompozitin bazı katmanlarında üçüncü (son) ARB döngüsünden sonra boyun verme gözlemlendi. Bu durum, katmanların birbirine geçerek daha güçlü bağlar oluşturduğunu gösterir. Kırılma yüzeylerinden alınan SEM görüntüleri yüksek gerinim uygulanan haddeleme döngüleri sebebiyle, arayüzlerde son haddeleme döngüsüne kadar azalarak devam eden katman ayrılmasını ortaya çıkardı. ARB döngülerinin sayısı arttıkça mikro sertlik seviyelerinde önemli bir iyileşme saptandı. ARB işleminden sonra titanyum ve IF çelik katmanları için sırasıyla 1.4 ve 2.6 kata kadar mikro sertlik artışı gözlemlendi. 400°C'de haddelenmiş Ti/IF çelik kompozitinin çekme mukavemeti, üç döngüden sonra 670MPa'yı aştı. APD proseslerinde beklendiği üzere, üç ARB döngüsünden sonra tüm durumlarda süneklik %5'in altına düşürülmüştür. SPT sonuçları, artan döngü sayısı ile numunenin kesme mukavemetininde arttığını gösterdi ve üç döngüden sonra yaklaşık 440MPa'lık bir maksimum kesme mukavemeti elde edildi. İkinci kısımda yapılan mikroyapısal inceleme uzun yaşlanmanın, üç döngülü ARB işlenik numune iç yapısındaki tanecik boyutunda kısmi büyümeye yol açtığı belirlendi. Ayrıca, uygulanan yaşlandırma sonrası, çökelti sertleşmesi sayesinde malzemenin çekme mukavvemetini kaybetmeden süneklik kazandığı gözlemlenmiştir. 150°C’de 24 saat yaşlandırmanın ardından maksimum çekme mukavemeti (UTS) yaklaşık 420MPa seviyesine yükseldi ve %18 süneklik elde edildi. Aynı şartlarda maksimum kesme mukavemeti 270MPa seviyesine kadar yükseldi. ARB prosesi sonlu elemanlar analizi temelinde Ansys Workbench kullanılarak modellendi. Efektif plastik gerinim ve gertime (von-Mises) değerlerinin ARB işlenik numunelerin kalınlığına göre değişim hesaplanmıştır. Deneysel bulgular ve sayısal analizlerin örtüştüğü gözlemlenmiştir
Search for singly and pair-produced leptoquarks coupling to third-generation fermions in proton-proton collisions at √s = 13 TeV
No full textA search for leptoquarks produced singly and in pairs in proton-proton collisions is presented. We consider the leptoquark (LQ) to be a scalar particle of charge −1/3e coupling to a top quark plus a tau lepton (tτ) or a bottom quark plus a neutrino (bν), or a vector particle of charge +2/3e, coupling to tν or bτ. These choices are motivated by models that can explain a series of anomalies observed in the measurement of B meson decays. In this analysis the signatures tτνb and tτν are probed, using data recorded by the CMS experiment at the CERN LHC at s=13 TeV and that correspond to an integrated luminosity of 137 fb−1. These signatures have not been previously explored in a dedicated search. The data are found to be in agreement with the standard model prediction. Lower limits at 95% confidence level are set on the LQ mass in the range 0.98–1.73 TeV, depending on the LQ spin and its coupling λ to a lepton and a quark, and assuming equal couplings for the two LQ decay modes considered. These are the most stringent constraints to date on the existence of leptoquarks in this scenario.BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MOST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RIF (Cyprus); SENESCYT (Ecuador); MoER, ERC PUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, ROSATOM, RAS, RFBR, and NRC KI (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI, and FEDER (Spain); MoSTR(Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 724704, 752730, and 765710 (European Union); the Leventis Foundation; theA.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S. -FNRS and FWO (Belgium) under the "Excellence of Science -EOS" -be.h project n. 30820817; the Beijing Municipal Science & Technology Commission, No. Z191100007219010; The Ministry of Education, Youth and Sports(MEYS) of the Czech Republic; the Deutsche Forschungsgemeinschaft (DFG) under Germany's Excellence Strategy -EXC 2121 "Quantum Universe" -390833306; the Lendulet ("Momentum") Program and the Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program UNKP, the NKFIA research grants 123842, 123959, 124845, 124850, 125105, 128713, 128786, and 129058 (Hungary); the Council of Science and Industrial Research, India; the HOMING PLUS program of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund, the Mobility Plus program of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund; the Ministry of Science and Higher Education of the Russian Federation, project no.
0723-2020-0041 (Russia); the Tomsk Polytechnic University Competitiveness Enhancement Program; the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia Maria de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Kavli Foundation; the Nvidia Corporation; the SuperMicro Corporation; the Welch Foundation, contract C1845; and the Weston Havens Foundation (USA).Publisher versio
Finite-SNR diversity gain analysis of FSO systems over gamma-gamma fading channels with pointing errors
No full textFree space optical (FSO) communication systems are subject to turbulence-induced fading as a result of fluctuations in the refractive index. Gamma-Gamma (GG) distribution is commonly used in the literature to characterize moderate-to-strong turbulence conditions. The performance of FSO systems is further degraded by pointing error-induced fading as a result of building sways. While the asymptotic analysis presented in earlier works is important to understand the maximum diversity gains of FSO systems attainable over fading channels, such gains might not be available in practical range of signal-to-noise ratio (SNR). Furthermore, different systems with the same asymptotic slope may have different slopes in the range of finite SNR values. In this paper, we consider a multiple-input multiple-output (MIMO) FSO system with intensity modulation and direct detection (IM/DD). We derive approximate expression for the finite-SNR diversity order over GG turbulence channels in the presence of pointing errors. We also investigate convergence speed to full diversity. We provide numerical results to demonstrate the accuracy of our derivations and corroborate on our analytical findings.TÜBİTAK ; Deanship of Scientific Research, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabi
The very forward CASTOR calorimeter of the CMS experiment
No full textThe physics motivation, detector design, triggers, calibration, alignment, simulation, and overall performance of the very forward CASTOR calorimeter of the CMS experiment are reviewed. The CASTOR Cherenkov sampling calorimeter is located very close to the LHC beam line, at a radial distance of about 1cm from the beam pipe, and at 14.4m from the CMS interaction point, covering the pseudorapidity range of -6.6 < η < -5.2. It was designed to withstand high ambient radiation and strong magnetic fields. The performance of the detector in measurements of forward energy density, jets, and processes characterized by rapidity gaps, is reviewed using data collected in proton and nuclear collisions at the LHC.Publisher versio
Rethinking temporal demand data to reduce distribution transformer losses: A case study from a Turkish DSO
No full textWith the increase in digital measurement and monitoring devices in the Turkish electricity grid, the possibilities of processing the obtained data and revealing meaningful information are also increasing. In this project, an optimization study is carried out on optimal sizing of transformers by using sub-hourly historical load data collected from transformers. In the study on transformer efficiency based on the regulations renewed in the last 10 years in Turkey, the core and copper losses of the transformers are estimated based on historical data, and the efficiency increase that would be provided in case of renewal of the transformers is calculated. According to the results obtained, it is predicted that transformer losses can be reduced by 50% and annual savings of approximately 1 kWh can be achieved for each dollar invested