5916 research outputs found
Sort by
X2V: 3D organ volume reconstruction from a planar X-Ray image with neural implicit methods
No full textIn this work, an innovative approach is proposed for three-dimensional (3D) organ volume reconstruction from a single planar X-ray, namely X2V network. Such capability holds pivotal clinical potential, especially in real-time image-guided radiotherapy, computer-aided surgery, and patient follow-up sessions. Traditional methods for 3D volume reconstruction from X-rays often require the utilization of statistical 3D organ templates, which are employed in 2D/3D registration. However, these methods may not accurately account for the variation in organ shapes across different subjects. Our X2V model overcomes this problem by leveraging neural implicit representation. A vision transformer model is integrated as an encoder network, specifically designed to direct and enhance attention to particular regions within the X-ray image. The reconstructed meshes exhibit a similar topology to the ground truth organ volume, demonstrating the ability of X2V in accurately capturing the 3D structure from a 2D image. The effectiveness of X2V is evaluated on lung X-rays using several metrics, including volumetric Intersection over Union (IoU). X2V outperforms the state-of-the-art method in the literature for lungs (DeepOrganNet) by about 7-9% achieving IoU's between 0.892-0.942 versus DeepOrganNet's IoU of 0.815-0.888.Publisher versio
Statistical characterization of SNR in RIS-Aided wireless communication systems
No full textReconfigurable intelligent surfaces (RISs) can significantly improve overall communication quality by mitigating the adverse effects of multipath fading, reducing interference, and extending coverage areas. Most existing works on RIS focus on far-field scenarios and large-scale RIS configurations, where the central limit theorem (CLT) is often used to approximate the distribution of the cascaded channels. However, such an approximation may not accurately reflect the performance of RIS in near-field conditions or when the number of reflecting elements is small. In this paper, we provide a statistical characterization of signal-to-noise ratio (SNR) in RIS-assisted wireless systems in near-field conditions with a small number of RIS elements. Our results demonstrate that Gamma distribution accurately depicts instantaneous SNR distribution. The proposed model provides an accurate tool for understanding and predicting the performance of RIS systems under diverse operational conditions
NOVLI-ISA: A novel optimized variable-length inclusive instruction set architecture for RV32I/E architecture
No full textThis paper proposes a Novel, Optimized Variable-Length Inclusive ISA for RV32I/E architectures, namely, NOVLI-ISA. The main objective of this work is to reduce the code size and, if possible, the power consumption. The proposed ISA introduces new general and tailored functions within its flexible structure. The proposed ISA is demonstrated using a sample RV32I CPU with the necessary hardware modifications. Furthermore, to evaluate its feasibility, a dedicated batch optimizer was implemented for machine code compression and quantitative analysis of typical storage reduction for different programs
Generative ai tools in design fields: Opportunities and challenges in the ideation process
No full textThe utilization of artificial intelligence (AI) tools in the arts and design is gaining increasing attention within the creative industries. This paper explores the growing integration of artificial intelligence (AI) tools in arts and design, focusing on the collaboration between designers and AI during the ideation process. Drawing insights from interviews with academics and graduate students from design-related departments at Ozyegin University, this study compares the ideation processes using generative AI design tools versus non-AI tools. The findings reveal that designers perceive generative AI tools as more efficient during brainstorming stages. Key themes emerged, including the use of chatbots, the importance of accurate verbal prompts, collaborative AI tools, and the acceleration of the creative process. However, concerns regarding the predictability of AI advancement were also expressed. These findings illuminate the evolving role of AI design tools in communication design academia, underscoring their collaborative impact on ideation processes in the digital era
Classification of teams based on production, goal and performance in teams implementing scrum framework
No full textPurpose: In agile teams, performance and the metrics involved are managed by team and individual goals. In agility, the focus is on team performance rather than individual performance. However, for team performance, the roles individuals play within the team and the work capacities they take on have a great impact on this performance. Not analyzing the work of individuals in the process of identifying the team's problems and improving performance may be contrary to the system analysis approach. Theory and Methods: The range expected to be examined in similar models is very wide, and there is no solution proposal for months-long conflicts and inefficient work outcomes. It is recommended to follow up with 8 team forms in the research, to include weekly follow-up unlike other models, to intervene in a shorter time and to intervene more quickly in the different dynamics of the teams.Results: Many reasons such as the departure of people within the team, the joining of new people to the team, changes in business priorities due to laws and regulations, and rapid changes in product strategy can invalidate the maturity models in the literature. The maturity measurement approach here includes what needs to be done until the ideal approach called team form-8 is reached. There is no consecutive structure from team form 1 to team form 8. Conclusion: The decisions to be taken and the strategies to be implemented within these analyzes will contribute to keeping agility in a sustainable structure. It is recommended that researchers follow the recommended form types long-term. Although maturity models of agile teams are made directly on the output, it is expected that examining the minimum features that teams must have for maturity and external dependency issues will contribute to the literature.Publisher versio
Exploring the impact of abusive supervision on employee approaches to managing service errors and failures: Examining the effects of hope and optimism, and service tenure
No full textDrawing from the conservation of resources (COR) theory, the current study posits that leadership in the form of abusive supervision will be more detrimental to subordinates' hope and optimism, due to the loss of accumulated resources for those who have increased service tenure, thereby lowering their ability to alleviate and successfully manage service failures/errors. Using convenience sampling, 174 hotel frontline employees from Istanbul, Turkey, completed survey questionnaires in two separate time waves. Results from SmartPLS indicate that abusive supervision has a significant and adverse association with employees' hope and optimism. Additionally, the relationship between abusive supervision and employees' hope and optimism is moderated by service tenure, such that the negative relationship is more profound for those with increased service tenure. Finally, hope and optimism mediate the relationship between abusive supervision and two behaviors for handling service errors/ failures (i.e., service recovery performance and error reporting). This study concludes by discussing theoretical and practical implications
KADEM’s vision of gender justice and neopatriarchal masculinity in illiberal Turkey
No full textWomen's and LGBTI + rights have always been under attack in Turkey, but recent developments in AKP's attempts to consolidate a pro-family, pro-birth, and Islamist gender regime based on the 'moral' regulation of women and LGBTI + creates an atmosphere that must be examined in detail. KADEM, a women's GONGO established in 2013, plays a crucial role in this anti-gender backlash context, positioning their line of action as a challenge to the global feminist attempts to impose Western standards on Turkish society while advocating for women's rights from a culturalist position. We analyse KADEM's construction of men and masculinities in the materials on their website to understand their strategies of legitimisation of a form of neopatriarchal masculinity along the traditional 'family values' to see how KADEM serves as a transmitter of an Islamic neopatriarchal culture, with its implicit justifications of men's patriarchal roles and duties in a neoliberal society.Norwegian Agency for Development Cooperation - NORA
Investigating the impact of postponement and stock-sharing strategies on prepositioned relief stocks
No full textPrepositioning is a critical disaster preparedness mechanism for humanitarian organizations (HOs) but requires significant investment. Improving the efficiency of prepositioned stocks is a primary concern within the humanitarian community. This study, conducted in collaboration with the Emergency Supply Prepositioning Strategy (ESUPS) Working Group, examines the impact of implementing postponement and stock-sharing strategies in a regional humanitarian warehouse. We focus on a setting where multiple HOs preposition supplies within the same warehouse to serve disaster-affected countries. Traditionally, these prepositioned supplies are branded with the respective HOs' logos, hindering the sharing of surplus stock during disaster response. Our system defers the branding process for a portion of the stockpile until after a disaster, facilitating the sharing of unbranded stock among HOs. To evaluate the benefits of postponement in this humanitarian context, we develop a two-phase inventory allocation framework for distributing branded and unbranded stocks to disaster-affected countries and for sharing unbranded stocks among HOs. We then incorporate our inventory allocation models into a Monte Carlo simulation algorithm that accounts for uncertainties regarding the occurrence and impact of disasters. Using a case study based on data from ESUPS members in the Caribbean region, we demonstrate that the proposed strategy can significantly enhance the efficiency and effectiveness of prepositioning. Remarkably, we observe a U-shaped relationship in response time as the postponement rate increases, while the fill rate and inventory utilization consistently improve. Our numerical study provides valuable insights for decision making in humanitarian logistics.TÜBİTAKPublisher versio
İç mekan ve araç milimetre dalgası (MMW) iletişimi için kanal modelleme ve karakterizasyonu.
No full textThe demand for ultra-high-speed wireless connectivity is ever-increasing, which poses unique challenges for the next-generation wireless communication system design. This has prompted the exploration of higher frequency bands including millimeter wave millimeter Wave (MMW) and visible light bands in addition to the conventional sub-6 GHz band. In this thesis, we provide a detailed comparison of these frequency bands’ propagation chan nels in identical indoor settings. We adopt ray tracing techniques for site-specific channel modeling, which enables the consideration of the three-dimensional models of the indoor environment and objects inside. Using ray tracing, we model site-specific channels in three-dimensional indoor environments, considering various frequencies (2.4 GHz to 100 GHz) and transmitter types (Radio Frequency (RF) antennas and indoor lighting for Visible Light Communication (VLC)). Our analysis includes Channel Impulse Response Channel Impulse Response (CIR) data, channel path losses, and Cumulative Distribution Function Cumulative Distribution Function (CDF) expressions for received power levels across all considered frequencies. Our results highlight that VLC channels demonstrate lower path loss than MMW but more than the 2.4 GHz band, while also revealing the impact of antenna types on MMW path loss, especially over shorter transmission distances. Vehicle to Vehicle (V2V) communication is an underlying key technology to realize future intelligent transportation systems. Both MMW communication and VLC are strong candidates to address V2V connectivity. Most of the earlier literature focuses on individual technology. In an effort to better highlight the differences and relative advantages of these two competing technologies, we provide a comprehensive one-to-one comparison between vehicular VLC and MMW channels in this thesis. For this purpose, we utilize ray tracing simulations which enable the consideration of three-dimensional modeling of the propa gation environment and allow the study of various system parameters and road conditions in both Line of Sight (LOS) and Non Line of Sight (NLOS) conditions. In the same set tings, we showcase the signal strengths for both systems and study their channel features for communication between vehicles in the same or different lanes, assessing the effects of varying densities of neighboring vehicles and instances of partial or complete blockage.Ust ¨ un hızda kablosuz ba ¨ glantı talebi s ˘ urekli artıyor, bu da gelecek nesil kablosuz iletis¸-im ¨ sistem tasarımı ic¸in benzersiz zorluklar doguruyor. Bunun ˘ uzerine, geleneksel alt-6 GHz ¨ bandına ek olarak milimetre dalga (MMW) ve gor¨ un¨ ur ıs¸ık bantları gibi y ¨ uksek frekanslı ¨ bantların kes¸fine yonelik c¸alıs¸malar hız kazandı. Bu aras¸tırma, aynı ic¸ mekan ayarlarında ¨ bu frekans bantlarının yayılma kanallarını detaylı bir s¸ekilde kars¸ılas¸tırıyor. Siteye ozg ¨ u¨ kanal modelleme ic¸in ıs¸ın izleme tekniklerini kullanıyoruz, bu da ic¸ mekanın uc¸ boyutlu ¨ modellerini ve ic¸indeki nesneleri dikkate alma imkanı saglıyor. 2.4 GHz ile 100 GHz ˘ arasındaki c¸es¸itli frekanslar ve Verici Frekansı (RF) antenleri ile Gor¨ un¨ ur Is¸ık ¨ ˙Iletis¸imi (VLC) ic¸in ic¸ mekan aydınlatma gibi farklı verici tiplerini goz¨ on¨ unde bulundurarak, ıs¸ın ¨ izleme ile siteye ozg ¨ u kanalları modelliyoruz. Analizimiz, Telsiz ¨ ˙Impuls Cevabı (CIR) verilerini, kanal yol kayıplarını ve alınan guc¸ seviyelerinin Kumulatif Da ¨ gılım Fonksiyonu ˘ (CDF) ifadelerini ic¸eriyor. Sonuc¸larımız, VLC kanallarının MMW’den daha dus¸¨ uk yol ¨ kaybına sahip oldugunu ancak 2.4 GHz bandından daha fazla oldu ˘ gunu g ˘ osterirken, aynı ¨ zamanda ozellikle kısa iletim mesafelerindeki MMW yol kaybına anten tiplerinin etkisini ¨ ortaya koyuyor. V2V iletis¸imi, gelecekteki akıllı ulas¸ım sistemlerini gerc¸ekles¸tirmek ic¸in temel bir ana htar teknolojidir. Hem MMW iletis¸imi hem de VLC, V2V baglantısını ele almaya g ˘ uc¸l ¨ u¨ adaylardır. Daha onceki literat ¨ ur¨ un c¸o ¨ gu bireysel teknolojiye odaklanmaktadır. Bu iki ˘ rakip teknolojinin farklılıklarını ve goreceli avantajlarını daha iyi vurgulamak amacıyla, ¨ bu tezde arac¸ VLC ve MMW kanalları arasında kapsamlı bire bir kars¸ılas¸tırma sunuy oruz. Bu amac¸la, yayılma ortamının uc¸ boyutlu modellemesinin dikkate alınmasına olanak ¨ tanıyan ve c¸es¸itli sistem parametrelerinin ve yol kos¸ullarının hem gor¨ us¸ hattı hem de g ¨ or¨ us hattı dıs¸ı kos¸ullarda incelenmesine olanak tanıyan ıs¸ın izleme simulasyonlarından yarar- ¨ lanıyoruz. Aynı ayarlar altında, her iki sistem ic¸in alınan sinyal guc¸lerini sunuyoruz ve aynı ¨ s¸eritte ve farklı s¸eritlerde bulunan iki arac¸ arasındaki iletis¸im ic¸in yanal kaydırma ile kanal ozelliklerini aras¸tırıyoruz. Ayrıca koms¸u arac¸ların d ¨ us¸¨ uk, orta ve y ¨ uksek yo ¨ gunlu ˘ gunun ˘ yanı sıra kısmi ve tam tıkanmaların etkisini de analiz ediyoruz
Influence of various corn syrup types on the quality and sensory properties of gelatin-based jelly confectionery
No full textJelly candies are soft confectionery products primarily composed of sucrose, corn syrup and gelling agents. This study investigates the impact of six different corn syrup, all used at constant amount (46.22%), on the physicochemical (moisture content, pH, Colour), texture and sensory properties of gelatin-based jelly samples. The Moisture content, pH, colour, and texture properties of samples were analysed at 0th, 15th, 30th, 45th, and 60th day during storage. Before storage moisture content of the candiesranged from21.03 to 22.57% whereas after 60 days, it was found between 19.31 and 20.72%. Sample JF42 exhibited the least moisture rate loss. The type of corn syrup did not significantly affect the pH of the samples. Samples with higher fructose content in the corn syrup had the lowest hardness, whereas the sample with the highest maltose content exhibited the highest hardness. Changes in gumminess and chewiness paralleled variations in hardness results. Hardness and gumminess were found suitable to follow up gelatin-based samples storage using the zero-order kinetics modelling. Corn syrups with high fructose amounts intensified the redness, while those with high glucose levels led to yellowness in the candies. In sensory evaluation, products made with G40, G60, and M50 corn syrups received higher general Understanding how various types of corn syrup impact the candies quality helps producers optimize their formulation. This information enables producers to mitigate quality deterioration during storage, ensuring that their candies maintain at the desired level and appeal to consumers.TÜBİTAKPublisher versio