Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 1Citation - Scopus: 1Experimental Investigation of Naca 4415 Airfoil Using Vibration Data for Stall Detection(Emerald Group Publishing, 2023) Ayaz Ümütlü, Hatice Cansu; Kıral, Zeki; Karadeniz, Ziya HaktanPurposeThe purpose of this study is to identify the possible relation between the vibration and the stall by using the vibration response of the airfoil. For this purpose, the root mean square values of the acceleration signals are evaluated to demonstrate the compatibility between the stall angles and the vibration levels. Design/methodology/approachAn experimental study is conducted on NACA 4415 airfoil at Reynolds numbers 69e3, 77e3 and 85e3. Experiments are performed from 0 & DEG; to 25 & DEG; of the angles of attack (AoA) for each Reynolds number condition. To observe the change of the vibration values at the stall region clearly, experiments are performed with the AoA ranging from 10 & DEG; to 25 & DEG; in 1 & DEG; increments. Three acceleration sensors are used to obtain the vibration data. FindingsThe results show that the increase in the amplitude of the vibration is directly related to the decrease in lift. These findings indicate that this approach could be beneficial in detecting stall on airfoil-type structures. Originality/valueThis study proposes a new approach for detecting stall over the airfoil using the vibration data.Article Citation - WoS: 3Citation - Scopus: 5Assessing Community Awareness for Participatory Conservation of Cultural Heritage: the Case of Tepebağ Tumulus and Its Surroundings in Adana Turkey(Emerald Group Publishing, 2022) Umar, Nur; Yüceer, Hülya; Aydın, RozelinPurpose: The purpose of this paper is to identify the levels of awareness of locals about conservation and cultural heritage, in order to develop suggestions and methods for them to participate in these processes. Design/methodology/approach: The method of research is based on face-to-face surveys, mainly questionnaires that were conducted with 1,200 local people. The data obtained was evaluated using the SPSS 25.0.0 V program. Findings: The results show that locals mainly find appropriate the assets that reflect their culture but disregard archaeological remains. The participation of locals in the conservation process will end up benefiting them economically. Social implications: It is currently accepted that effective conservation cannot be achieved unless its technical considerations are considered together with social and cultural aspects. Ensuring the participation of local people in the conservation process has proved to be important in the development of holistic and sustainable outcomes. In places, where multilayered cultural heritage exists and local residents are from different cultural backgrounds, a detailed assessment of cultural heritage perception that involves local people gains significance. Originality/value: It is project-based in the sense of adding the dimension of community awareness to the practice of cultural heritage conservation in the multilayered and multicultural places.Article Citation - WoS: 6Citation - Scopus: 9Gendered Sense of Safety and Coping Strategies in Public Places: a Study in Atatürk Meydanı of Izmir(Emerald Group Publishing, 2022) Şenol, FatmaPurpose: A threatened sense of safety in public spaces is a problem for liveable communities. For better public policies, this study investigates multi-dimensional and multi-scalar aspects of gendered perceived safety and strategies by women and men in daily public spaces. Design/methodology/approach: A face-to-face survey with 40 men and 50 women in a public space (Izmir, Turkey) is deployed. Descriptive statistics and regression analysis compare participants' perceptions of and strategies for safety across the city, neighbourhood and the study site. Findings: Their experienced-based familiarities in public places increase women's perceived safety. As safety strategies, different place-based and gendered-preconditions appear for women and men going “outside” especially “alone” (i.e. unaccompanied). Reaffirming female vulnerability in public places, gendered preconditions include individuals' attributes. Of place-based preconditions, crowd and police are significant mechanisms for safety but emphasized differently by women and men. Housewives' female companionship in the study site develops a class- and gender-based claim for a safe place away from their underserved neighbourhood. Practical implications: Gendered- and place preconditions for women's safety can inform design policies about surveillance and permeability of public spaces. Lack of data about class-based differences about perceived safety is a limitation. Originality/value: Among a few, it takes perceived safety as performative acts with learned strategies across (rather than momentary perceptions in) socio-spatial spaces and provides a research framework that considers such acts with individual and spatial dimensions across multiple socio-spatial scales.Article Citation - WoS: 2Citation - Scopus: 3Model-Based Detection and Isolation of the Wheel Slippage and Actuator Faults of a Holonomic Mobile Robot(Emerald Group Publishing, 2022) Şahin, Osman Nuri; Dede, Mehmet İsmet CanPurpose: Mobile robots may perform very critical tasks under difficult operating conditions. Faults encountered during their tasks may cause the task to be interrupted or failed completely. In the active fault tolerant control methods, it is very important not only to detect the faults that occur in the robot, but also to isolate these faults to develop a fault recovery strategy that is suitable for that specific type of fault. This study aims to develop a model-based fault detection and isolation method for wheel slippage and motor performance degradation that may occur in wheeled mobile robots. Design/methodology/approach: In the proposed method, wheel speeds can be estimated via the dynamic model of the mobile robot, which includes a friction model between the wheel and the ground. Four residual signals are obtained from the differences between the estimated states and the measured states of the mobile robot. Mobile robot’s faults are detected by using these signals. Also, two different residual signals are generated from the calculation of the traction forces with two different procedures. These six residual signals are then used to isolate possible wheel slippage and performance degradation in a motor. Findings: The proposed method for diagnosing wheel slip and performance degradation in motors are tested by moving the robot in various directions. According to the data obtained from the test results, a logic table is created to isolate these two faults from each other. Thanks to the created logic table, slippage in any wheel and performance degradation in any motor can be detected and isolated. Originality/value: Two different recovery strategies are needed to recover temporary wheel slippage and permanent motor faults. Therefore, it is important to isolate these two faults that create similar symptoms in robot’s general movement. Thanks to the method proposed in this study, it is not only possible to isolate the slipping wheel with respect to the non-slipping wheels or to isolate the faulty motor from the non-faulty ones, but also to isolate these two different fault types from each other.Article Citation - WoS: 5Citation - Scopus: 4A Quantitative Approach for Evaluating Intervention-Value Relations: Historic Mosques of Manisa, Turkey(Emerald Group Publishing, 2021) Büyükkılıç Koşun, Suna; Hamamcıoğlu Turan, MinePurpose This study aims to propose a systematic way of evaluating the impact of historic and current interventions on cultural asset values of monuments that have preserved their authentic functions so that future interventions can be better guided. Design/methodology/approach The study focuses on the Mosque typology. The case studies are chosen from a region that has a rich historic background, but has generally undergone rapid urbanization and faces extensive restorations today. Conventional site survey, archive and historical research and visual analysis are made, but the evaluation process has been designed. As a result, scale and intensity of interventions and disasters and the vulnerability of the monument should be identified for each period of the asset. Variations in the intensity of esthetic or historic qualities and the environmental settings should be credited, rather than the utilitarian necessities. Findings Mosques and their environs are most vulnerable in terms of their architectural authenticity and site aesthetics. Originality/value The objects studied in the previous studies present a variation, but the majority of the work is carried out with conventional evaluation methods with the emphasis on building scale. However, the mosques are affected by the interventions and disasters, not only as single architectural entities but also as the focal elements of their neighborhoods. So, the intervention-value relations should be understood both for building and site scales. An evaluation process is proposed for understanding the change of values with respect to interventions and disasters throughout history by combining qualitative and quantitative techniques.Article Citation - WoS: 12Citation - Scopus: 12Numerical Determination of Interfacial Heat Transfer Coefficient for an Aligned Dual Scale Porous Medium(Emerald Group Publishing, 2018) Sabet, Safa; Mobedi, Moghtada; Barışık, Murat; Nakayama, AkiraPurpose Fluid flow and heat transfer in a dual scale porous media is investigated to determine the interfacial convective heat transfer coefficient, numerically. The studied porous media is a periodic dual scale porous media. It consists of the square rods which are permeable in an aligned arrangement. It is aimed to observe the enhancement of heat transfer through the porous media, which is important for thermal designers, by inserting intra-pores into the square rods. A special attention is given to the roles of size and number of intra-pores on the heat transfer enhancement through the dual scale porous media. The role of intra-pores on the pressure drop of air flow through porous media is also investigated by calculation and comparison of the friction coefficient. Design/methodology/approach To calculate the interfacial convective heat transfer coefficient, the governing equations which are continuity, momentum and energy equations are solved to determine velocity, pressure and temperature fields. As the dual scale porous structure is periodic, a representative elementary volume is generated, and the governing equations are numerically solved for the selected representative volume. By using the obtained velocity, pressure and temperature fields and using volume average definition, the volume average of aforementioned parameters is calculated and upscaled. Then, the interfacial convective heat transfer coefficient and the friction coefficient is numerically determined. The interparticle porosity is changed between 0.4 and 0.75, while the intraparticle varies between 0.2 and 0.75 to explore the effect of intra-pore on heat transfer enhancement. Findings The obtained Nusselt number values are compared with corresponding mono-scale porous media, and it is found that heat transfer through a porous medium can be enhanced threefold (without the increase of pressure drop) by inserting intraparticle pores in flow direction. For the porous media with low values of interparticle porosity (i.e. = 0.4), an optimum intraparticle porosity exists for which the highest heat transfer enhancement can be achieved. This value was found around 0.3 when the interparticle porosity was 0.4. Research limitations/implications The results of the study are interesting, especially from heat transfer enhancement point of view. However, further studies are required. For instance, studies should be performed to analyze the rate of the heat transfer enhancement for different shapes and arrangements of particles and a wider range of porosity. The other important parameter influencing heat transfer enhancement is the direction of pores. In the present study, the intraparticle pores are in flow direction; hence, the enhancement rate of heat transfer for different directions of pores must also be investigated. Practical implications The application of dual scale porous media is widely faced in daily life, nature and industry. The flowing of a fluid through a fiber mat, woven fiber bundles, multifilament textile fibers, oil filters and fractured porous media are some examples for the application of the heat and fluid flow through a dual scale porous media. Heat transfer enhancement. Social implications The enhancement of heat transfer is a significant topic that gained the attention of researchers in recent years. The importance of topic increases day-by-day because of further demands for downsizing of thermal equipment and heat recovery devices. The aim of thermal designers is to enhance heat transfer rate in thermal devices and to reduce their volume (and/or weight in some applications) by using lower mechanical power for cooling. Originality/value The present study might be the first study on determination of thermal transport properties of dual scale porous media yielded interesting results such as considerable enhancement of heat transfer by using proper intraparticle channels in a porous medium.Article Citation - WoS: 6Citation - Scopus: 9Process Ontology Development Using Natural Language Processing: a Multiple Case Study(Emerald Group Publishing, 2019) Gürbüz, Özge; Rabhi, Fethi; Demirörs, OnurPurpose: Integrating ontologies with process modeling has gained increasing attention in recent years since it enhances data representations and makes it easier to query, store and reuse knowledge at the semantic level. The authors focused on a process and ontology integration approach by extracting the activities, roles and other concepts related to the process models from organizational sources using natural language processing techniques. As part of this study, a process ontology population (PrOnPo) methodology and tool is developed, which uses natural language parsers for extracting and interpreting the sentences and populating an event-driven process chain ontology in a fully automated or semi-automated (user assisted) manner. The purpose of this paper is to present applications of PrOnPo tool in different domains. Design/methodology/approach: A multiple case study is conducted by selecting five different domains with different types of guidelines. Process ontologies are developed using the PrOnPo tool in a semi-automated and fully automated fashion and manually. The resulting ontologies are compared and evaluated in terms of time-effort and recall-precision metrics. Findings: From five different domains, the results give an average of 70 percent recall and 80 percent precision for fully automated usage of the PrOnPo tool, showing that it is applicable and generalizable. In terms of efficiency, the effort spent for process ontology development is decreased from 250 person-minutes to 57 person-minutes (semi-automated). Originality/value: The PrOnPo tool is the first one to automatically generate integrated process ontologies and process models from guidelines written in natural language. © 2018, Emerald Publishing Limited.