On the Communication Cost of MDS Erasure Codes in Distributed Storage Systems

Distributed storage systems store some redundant data to keep the degree of availability of the stored data constant and also to increase the system's resistance against failures. This type of systems usually use pure replication or methods based on RAID systems as redundancy schemes. In this paper, we study the communication cost of a distributed data storage system using Maximum Distance Separable (MDS) erasure codes. Our focus is reduction of the cost of one-to-many communication used in data reconstruction/repair initialization and update operations. We propose the use of two different communication approaches on the area of distributed storage systems for the above operations; Steiner tree approach and multi-shortest path approach. We also analyse these two communication approaches empirically and theoretically. Our theoretical results indicate that Steiner tree approach has lower message usage, whereas, multi-shortest path approach has lower time usage for data reconstruction/repair initialization operations. On the other hand, Steiner tree approach has better message and time metrics for the data update process. Furthermore, our experimental results support these theoretical results. Thus, users can choose between the two approaches depending on their needs and priorities

Gaining Strength For A New Future: Bosnia And Herzegovinas Export Opportunities

International trade is crucial for Bosnia and Herzegovinas (B&H) economic prosperity. In this study guidance to B&H exporters is provided by identifying potential markets and products to focus on when designing future trade strategies. To this end trends in the world trade and trade patterns are examined using various approaches.First approach to identify the potential markets for the B&H exports called for identifying the countries with highest general demand for Bosnia and Herzegovinas current export products. The products Bosnia and Herzegovina exports most along with the countries that demand these products the most in the world are identified. The second approach for identifying the potential export markets for B&H products examine the import volumes of other countries in the world. Still a more fruitful approach for the B&H exporters, at least in the short term, is to target the markets with the fastest growth of import volumes (the third approach). In the fourth approach, untapped trade and highly untapped trade countries that should be targeted by B&H exporters are presented. The fifth approach for identifying the potential export markets for B&H products is based on examining the products whose imports increased fastest in recent years and the countries that imported these products most.The products/product groups that have the highest potential for B&H export success are also identified. First, most imported products as well as the products/product groups whose exports increased the fastest in recent years are examined. Second, the import volumes ten countries with the highest total imports are examined on a product basis to identify the products they import most as well as the products with the highest growth rate of imports. Third, product categories with untapped trade potential and highly untapped trade potential along with their respective markets are presented.Long term sustainable success in the ever changing global economy requires a close and continuous scanning of the trends in the environment. The analysis approaches described above provide B&H exporters a starting point in evaluating their product and market selection strategies and designing new ones for the future

The Born Global Entrepreneur In Emerging Economies

As emerging economies increasingly participate in the global economy, Born Global firms from these countries are becoming significant players as well. In the literature, topics related to Born Global firms from emerging economies have mostly been overlooked. The purpose of this paper is to address part of this gap by studying the Born Global entrepreneur within the context of an emerging market. Specifically, the Born Global entrepreneur’s knowledge and behaviors required to start a Born Global firm in an emerging market as well as the success factors in the global marketplace are examined

Maritime Students' Assessment of Distance Education During the COVID-19 Pandemic

The coronavirus diseases-2019 (COVID-19) outbreak emerged in late 2019 and rapidly spread worldwide, resulting in a pandemic. The pandemic has had negative impacts on various aspects of life, particularly health and the economy. Education sector has been severely affected, as well. In Türkiye, as in many countries, face-to-face classes were replaced with distance education as a safety measure against the pandemic. Maritime education places significant emphasis on providing practical, hands-on training to its students. However, due to the COVID-19 pandemic, a shift to distance education was required, including the teaching of applied courses in this field of study. In this regard, revealing the evaluations of maritime students on distance education is an important issue that needs to be studied. Therefore, this study aims to evaluate the opinions of maritime faculty students in Türkiye regarding the technical aspects and learning process of the distance education that they received during the pandemic. To this end, the 'Distance Education Evaluation Scale' was administered to students via an online platform, and the resulting data were analyzed using SPSS Statistics 25. The results show that male students have a more positive evaluation of distance education than female students. Those who participate in distance education by using mobile phones have a more negative evaluation of distance education, while successful students have a more positive evaluation of distance education. Finally, there was no significant difference according to universities and classes

High strain rate response of nanofiber interlayered structural composites

Nanofibrous interlayer toughening strategy for laminated composite materials typically demonstrated at quasi-static loading is here evaluated under high strain rate deformation. Carbon fiber reinforced composite laminates of (0/90)25s stacking sequence are interlayered by polystyrene-co-glycidyl methacrylate (P(St-co-GMA)) nanofibers which are chemically tuned for interfacial compatibility when embedded in epoxy matrix. The cubical composite specimens are cut and subjected to high strain-rate deformation via Split Hopkinson pressure bar testing. Specimens are hit at their through-the-thickness (stacking) and side-to-side (in-plane) directions. The change in the dissipation of energy due to altered interlaminar microstructure is monitored and reported. Enhancement in the capacity of the energy dissipation due to the nanofibrous interlayers is as high as 80% in-plane and 40% through thickness directions, depending on the strain rate. The results overall suggest that interlayer toughening strategy used in this work prevents the formation of critical matrix cracks that can cause the formation of instantaneous mode II delamination. Incorporation of the nanofibers without causing notable weight penalty effectively toug

ZEMİN GERİLMELERİNİN SAYISAL GERİLME ÇÖZÜMLEMESİ YÖNTEMİYLE TAHMİNİ

Bu çalışmada tekil ve uniform yükün temel zemini üzerinde oluşturdukları gerilmeler sayısal gerilme çözümlemesi yöntemiyle bilgisayar ortamında modellendi. Zeminlerin elek analizi, kıvam limit değerleri, optimum su muhtevası, maksimum kuru birim hacim ağırlık ve şişme yüzdeleri belirlendi. Sonuç olarak; Phase2 bilgisayar programı ile modellenen zeminlerde uniform yük altında oluşan gerilme dağılımı ile tekil yük altındaki gerilme dağılımı arasında farklar gözlendi. Her iki yükün gösterdiği gerilme değerleri zemin emniyet gerilmesinden düşük olduğu anlaşıldı. Böylece sayısal gerilme çözümlemesi yöntemi sayesinde çok daha kısa sürede yapı–zemin etkileşimi ve zemin gerilme değerleri belirlenmiş oldu

ZEMİNLERİN PERMEABİLİTE KATSAYISI VE KONSOLİDASYON ÖZELLİKLERİ ÜZERİNE BİR ÇALIŞMA: ELAZIĞ ÖRNEĞİ

Bu çalışmada, fiziksel özellikleri belirlenen zeminler üzerinde permeabilite katsayısı ve konsolidasyon özelliklerinin belirlenmesi amaçlanmıştır. Proktor cihazıyla deney numuneleri elde edilmiştir. Proktor kabında sıkıştırılmış deney numunelerinden alınan örnekler üzerinde permeabilite ve konsolidasyon deneyleri yapılmıştır. Elde edilen bulgular dikkate alınarak, zeminlerin permeabilite ve konsolidasyon değerlerine göre rasyonel çözüm önerilerinde bulunulmuştur

BİR TIP FAKÜLTESİ UYGULAMA VE ARAŞTIRMA HASTANESİNDE SERVQUAL METODU YARDIMIYLA SAĞLIK HİZMETİ ALAN MÜŞTERİLERİN BEKLENTİLERİNİN ANALİZİ

It is essential that the response of demand and expectations of customers in health care services given in a hospital. In this study, it is tried to measure patients (customers) satisfaction by using a model has been designed to determine the quality of service in a research and practice hospital in Konya. Servqual which is the common and efficient method in the way of measuring service quality is utilized. It is applied a questionarrie included 22 question in 5 dimensions at the 7 level of Likertscale.Sağlık hizmetlerinde, hizmet sunulan bir hastanede hizmeti alan müşterilerin talep ve beklentilerininkarşılanması esastır. Bu araştırmada bir üniversitenin tıp fakültesi uygulama ve araştırma hastanesinde ayakta tedavi hizmeti alan hastaların (müşterilerin) beklentileri analiz edilerek müşteri memnuniyeti ölçülmeye çalışılmıştır. Müşteri beklentilerinin analizinde, son yıllarda etkinbir şekilde kullanılan SERVQUAL (Service Quality)metodu kullanılmıştır.Müşterilerin hizmet algıları ile beklentilerinin arasındaki farkın irdelenmesi için yedili likert ölçeğinde beş boyutta ve 22 sorudan oluşan bir anket uygulanmıştır

Anterior uterocervical angle: is it an ultrasonographic screening tool that estimates the latent phase duration in post term pregnancies?

Objectives: In recent years, in addition to cervical length measurement, a new ultrasonographic parameter has been defined  as uterocervical angle (UCA), which can be used in the prediction of preterm labor. In this study,we evaluated the place of uterocervical angle in predicting the latent phase duration in postterm pregnancies. Material and methods: This prospective study consists of 90 pregnant women aged between 18 to 40 years who were hospitalized with a diagnose of late term pregnancy. Pregnant women with a latent phase duration of 1200 minutes or less were defined as Group 1. Patients with latent phase duration over 1200 minutes were defined as Group 2. All patients’ age, BMI, smoke, cervical length measurements, uterocervical angle, latent and active phase of labor durations, length of the third stage and delivery types were compared. Results: The UCA median value of group 1 was 120 (94–147), and group 2 was 99 (94–105) (p < 0.001). CL medians of Groups 1 and 2 were 29 (17–43) and 28 (27–41) respectively (p: 0.871). UCA (AUC: 0.917, p < 0.0001) significantly predicted prolonged latent phase duration. Optimal cut off value was obtained at the value of 105 degree (100% sensitivity, 75% specificity) for UCA. Kaplan-Meier survival analysis showed that duration of labor was significantly higher in a group with low UCA (p: 0.013). Discussion: UCA can be a successful tool that can be used to predict duration of labor in cases of postterm pregnancies with medical induction

Periodontitis ile ilişkili trabeküler kemik değişikliklerinin fraktal analiz ile incelenmesi

Amaç: Periodontitis kemik ve diş dokularını etkileyen patolojik bir süreçtir bu nedenle trabeküler kemik yapısı da etkilenmiş olabilir. Kemik yıkımının erken teşhisi tedavi planını etkiler ve kemik yıkımının önüne geçilmesinde önemlidir. Fraktal analiz fraktal yapıların karmaşıklığını tarif etmek için geliştirilmiş bir doku analizidir. Bu çalışmanın amacı sağlıklı diş etine sahip hastalar ile periodontitisli hastaların trabeküler kemik yapılarının Konik Işınlı Bilgisayarlı Tomografi (KIBT) görüntüleri üzerinden fraktal analiz ile incelenmesidir. Gereç ve Yöntemler: 96 hastaya ait kayıtlar retrospektif olarak incelendi. Hastalar klinik ve radyolojik bulgular yardımıyla iki gruba ayrıldı. Mandibular birinci molar ve ikinci premolar dişin ortasındaki multiplanar KIBT kesitleri belirlendi. 64x64 piksel boyutundaki ilgili alanlar mandibular kanalın yukarısında, trabeküler kemiğin içerisinde olacak şekilde seçildi. Fraktal analiz kutu sayma metodu ile gerçekleştirildi. Bulgular: Sağlıklı dişetine sahip hasta grubunun ortalama fraktal boyut (FB) değeri 1.22 (±0.07), periodontitis hasta grubunun ortalama FB değeri 1.25 (±0.1) olarak bulunmuştur. Sağlıklı dişeti grubu ve periodontitis grubunun yaş ortalamaları 39.54 (±8.33) ve 43.72 (±10.53) idi. Sonuç: Sağlıklı dişetine sahip hastalar ile periodontitis hastalarının FB değerleri arasında anlamlı bir farklılık bulunamamıştır (p>0.05). Daha yüksek hasta sayısına sahip ve hem konvansiyonel radyografi hem KIBT kullanılarak yapılan fraktal analiz çalışmaları hastalık süreci ve kemik yapısına etkisi hakkında daha çok bilgi verecektir. ANAHTAR KELİMELER  Periodontitis, Erişkin Periodontitis, sünger kemik, Konik ışınlı bilgisayarlı tomograf