Browsing by Author "Metin, Bilgin."
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Item A decision support system for inventory management of information technology spare parts(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2015., 2015.) Turan, Aycan.; Metin, Bilgin.Rising operational costs have become a major issue in developing countries, causing many leading information technology (IT) companies to focus on inventory optimization. This thesis research concentrates on inventory policy optimization and decision making process. We develop a decision support system (DSS) that provides an optimal control of IT spare part inventory to minimize the total cost. The system supports a continuous review (Q, r) inventory policy and a periodic review (S, s) inventory policy options for managing the spare parts inventory. The DSS includes a forecast model to estimate the failure rates of different device types purchased in different time periods. It is also enhanced by a simulation environment which evaluates different inventory management scenarios and choses the optimum one. Next, the DSS is applied to a real system and optimum inventory management scenario is determined according to the cost and service performances. Experimental design analysis is performed to measure the sensitivity of optimal total cost with respect to input parameters such as inventory holding cost, part order cost and penalties. The DSS provides an efficient, effective and flexible decision making environment for the optimal control of IT spare parts.Item An agent-based phishing attack model from a human-organizational- technical perspective(Thesis (Ph.D.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2023., 2023) Mutlutürk, Meltem Emine.; Metin, Bilgin.In the rapidly evolving digital landscape, cybersecurity has emerged as a significant concern for organizations. This thesis delves into the intricate dynamics of malware-based phishing attacks on enterprise computer networks. Utilizing the robust methodological tool of Agent-Based Modelling (ABM), the research is firmly rooted in socio-technical theory and the concept of complex adaptive systems (CAS). The study meticulously examines the pivotal role of human factors, particularly awareness training and the credibility of phishing emails, in determining susceptibility to phishing attacks. Also, it underscores the significant impact of technological countermeasures, including the strategic deployment of Endpoint Detection and Response (EDR) solutions and the implementation of a hybrid antivirus scan policy, in mitigating infection rates. By seamlessly integrating human behaviour with socio- technical dimensions, the research provides a nuanced, comprehensive understanding of cybersecurity threats. The findings underscore the necessity for a balanced, holistic approach that equally prioritizes human behaviour and technological measures. This approach is crucial to enhance organizational resilience against relentless cyber threats. The insights gained from this research offer invaluable guidance for organizations striving to navigate the complex cybersecurity challenges in today's increasingly digital age.Item Cyber insurance adoption in SMEs as a risk management tool in digitalization(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in Social Sciences, 2022., 2022.) Özkeleş Yıldırım, Aslı.; Metin, Bilgin.; Taşkın, Nazım.Small – medium sized enterprises (SMEs) create the backbone of the Turkish economy. Digitalization is a key advancement for SMEs in order to create efficiency and open up new opportunities for innovation. However, digitalization makes SMEs vulnerable to cyber threats by opening an outlet to other systems. The lack of awareness of cyber protection and the increasing advancements in cyberattacks puts SMEs at risk of data breaches which in turn causes damage to the company. Cyber insurance is considered a risk management tool for the coverage of costs in the event of an unexpected cyber incident. Even though the coverages are beneficial for the insured, the cyber insurance market is far from reaching its full potential. The study aims to find the factors of cyber insurance adoption for SMEs and the effects of cyber insurance on digitalization through cyber readiness, organizational security performance and information and communication technologies (ICT) adoption. The model created for the study was based on technology-organization-environment (TOE) context extended with individual context and the post adoption effects of cyber insurance. A quantitative survey aimed towards SMEs was conducted to test the model. Methods for increasing adoption of cyber insurance among SMEs were suggested based on the model outcomes.Item Electronic tunability in analog filters(Thesis (Ph.D.)-Bogazici University. Institute for Graduate Studies in Science and Engineering, 2007., 2007.) Metin, Bilgin.; Çiçekoğlu, Oğuzhan.In the beginning years of the analog design, discrete components were being used in the analog design procedures. After manufacturing, trimmer capacitors and potentiometers were used for electronic tunability to compensate for the electronic component nonidealities and tolerances. After 1970s, analog circuits have been implemented as integrated circuits, where element tolerances are unacceptably high. Non-idealities and parasitics due to IC implementation are serious problems for the circuits after manufacturing. Therefore, electronic tuning of some parameters after production has been a very important feature in IC design. In the thesis following major tunability methods are examined: Electronic tunability with MOSFET-C technique, with mixed translinear loops, with operational transconductance amplifiers and with adjusting current-gain. During electronic tuning of the desired parameters, some other parameters of the circuit such as linearity, stability, gain and high frequency performance, may be affected in an undesired way. Therefore, trade-offs between tunability and other parameters of the circuits are illustrated to find effective tunability ranges. Moreover, in the thesis new tunable filter circuits are suggested for each of these methods as examples and detailed non-ideality and parasitic component analyses of these circuits are given.Item Enabling domestic digital transformation:|A methodology for determining the country of origin of IT products(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2019., 2019.) Özdemir, Serkan.; Metin, Bilgin.Digital transformation enhancement in IT sector is getting crucial for efficient solutions in organizations. Institutions in public sector try to enrich its process solutions with additional products and services. On the other hand, in order to reduce financial expenses, especially developing countries give high emphasis on obtaining products with domestic resources. In addition to that, it becomes crucial for public and military institutions to develop IT products and technology infrastructure with domestic resources in order to preserve data security and privacy. The recent actions from Google company to ban Android products for Huawei smartphone producer for security reasons and United States withdraw for F-35 fighter jets sales to Turkey for strategic data privacy reasons give clue about the importance of domestic production. Thus, there is a need to develop a reliable scale to measure domesticity of products. This study attempts to construct a methodology for determining country of origin of IT products. Suggested methodology was verified by interviews with experts in subject area.Item Evaluating and designing an internal control system for information systems processes using control self-assessment, 2014(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2014., 2014.) Yıldırım, Tuğba.; Metin, Bilgin.Information systems take its crucial role in the heart of business life today. Most of the business operations are held via information technology. Achievement of business objectives are strictly related with information systems (IS) internal control system in order to create effective and efficient business processes. It is very important for organizations to prevent undesirable events and operate activities effectively and efficiently in achieving business objectives. Fraud events took place in some of reputable organizations and the reasons for these events are concluded to be the lack of risk management and effective internal control system. After these fraudulent events in organizations, frameworks developed to manage risks and reconstruct their internal control systems. Designing an effective risk management and an internal control system is proposed as a solution for more effective and efficient operations. Recently, information systems became very important in operational activities since most of them are done by information technology. This dependency forced organizations to manage risks related with information systems and establish an IS internal control system. Control objectives for minimizing risks, their control practices and test steps of these controls are provided in reference guides. Control objectives are located under the IS processes. Risk and control specialists deal with risks in these processes and controls to minimize them. They are expected to work on making organizations compliant with related laws and regulations as well as internal policies and rules by designing controls. Several information can be found about importance of complying with the standards, frameworks, IS internal control system, control objectives, control practices. However, studies lack the answer for “How” to design internal control system in compliance with related frameworks and standards. This thesis provides an answer for the question of “How to design IS internal control system?” In this study “Control Self-Assessment Method” is proposed as an effective method by mentioning essential critical IS processes. Control Self-Assessment method is selected since it provides a flexible solution which is especially appropriate for designing an internal control system to achieve changing objectives of the companies.Item Privacy concerns on mobile applications Vis-À-Vis the number of permissions requested by android apps(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2019., 2019.) Rabea, Ala.; Metin, Bilgin.Since the introduction of smartphones and applications, privacy concerns have been rapidly rising. Today, over one billion people use smartphones with millions of apps. These apps may request different permissions from users. Whether it’s Android, IOS, Windows, or any other mobile operating system, apps may mostly request permissions more than necessary. In this study, Android apps from Google Play Store are examined. Python scraping code was used to collect details for over 5,000 apps including different parameters such as permissions requested and number of installs. The data was then analyzed using SPSS, AMOS, and Power BI. The analyses made varied from simple descriptive, to one-way ANOVA, multiple regression, and correlation. Also, graphs were constructed. Data analysis was fruitful and different hypothesis were significantly. The results showed that number of permissions requested is correlated with several other variables such as number of reviews, number of installs, and review score. Also, ANOVA tests showed that different developers and categories can possess statistically different number of permissions requested. The study has several limitations such as the IP address of the computer used in Turkey. Turkish apps were suggested. Also, the number of apps collected was 5,264 which relative to total number of apps on the store might be considered as small and non-representative.Item The effect of employees’ information security familiarity on their security incident awareness(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2018., 2018.) Tanrıverdi, Nur Sena.; Metin, Bilgin.Finding more sophisticated and effective solutions to protect data and information systems against advanced security threat is essential in both theory and practice. Technologies and laws are evolved to have more useful, robust and smarter protection methods. Also, researchers investigate human element of information security to measure people’s behavior and security awareness level. In this study, whether employees are capable to be a part of information security protection in their companies is investigated. Firstly, effect of information security familiarity on security incident awareness is discussed, then how security incident awareness affects security behavior is attempted to analyze. Implications of this study can help to improve employees’ behavior without any distinction between professions as well as information security awareness education and training programs. For this purpose, detailed literature review has been conducted and research model has been developed. Primary data source of this study is a survey. In order to develop questions for the survey, security experts’ opinion has been consulted besides literature studies. An online survey has been conducted on employees who work in companies located in Turkey. Totally 315 responses have been used to conduct analyses which have been applied to test five hypotheses proposed in this study.Item The technical challenges of cloud computing and their effects on usage(Thesis (M.A.) - Bogazici University. Institute for Graduate Studies in the Social Sciences, 2014., 2014.) Baktır, Ahmet Cihat.; Metin, Bilgin.Cloud computing is a computer technology that enable convenient, on demand and pay-as-you-go access to a pool of shared resources. Recently, cloud computing is taken into consideration by the companies that operate in many different sectors. It has an important role in the competition between the companies as it grows and increases the efficiency of companies by providing advantages more than in-house system. However, number of researches and studies about cloud computing is relatively less in Turkey than other countries. A considerable amount of companies are still not eager to adopt the cloud computing because besides advantages it provides, there are also several crucial challenges that are seen as a barrier to use cloud computing. The aim of this study is analyzing the technical challenges of cloud computing and their effects on usage in companies that operate in Turkey. The technical challenges that are analyzed in this study are gathered and classified by studying the related researches. The analysis results examine that whether Information Technology (IT) personnel in Turkey are aware of these challenges and these challenges affect the usage of cloud computing within their organization. According to the findings, the challenges about cloud applications and cloud migration negatively affect the usage of cloud computing while the challenges about privacy and security, account control, cloud structure, virtualization, monitoring, Internet connection and SLA do not affect the usage of cloud computing in negative way.