Special Topics in Information Technology

This open access book presents thirteen outstanding doctoral dissertations in Information Technology from the Department of Electronics, Information and Bioengineering, Politecnico di Milano, Italy. Information Technology has always been highly interdisciplinary, as many aspects have to be considered in IT systems. The doctoral studies program in IT at Politecnico di Milano emphasizes this interdisciplinary nature, which is becoming more and more important in recent technological advances, in collaborative projects, and in the education of young researchers. Accordingly, the focus of advanced research is on pursuing a rigorous approach to specific research topics starting from a broad background in various areas of Information Technology, especially Computer Science and Engineering, Electronics, Systems and Control, and Telecommunications. Each year, more than 50 PhDs graduate from the program. This book gathers the outcomes of the thirteen best theses defended in 2020-21 and selected for the IT PhD Award. Each of the authors provides a chapter summarizing his/her findings, including an introduction, description of methods, main achievements and future work on the topic. Hence, the book provides a cutting-edge overview of the latest research trends in Information Technology at Politecnico di Milano, presented in an easy-to-read format that will also appeal to non-specialists

A Success Case of Samsung Electronics in the Smartphone Industry

학위논문(석사) -- 서울대학교대학원 : 국제대학원 국제학과(국제통상전공), 2022. 8. Ahn, Jaebin.선진국의 기업 다각화에 관한 문헌은 관련 다각화의 이점과 기업 성과에 대한 긍정적인 영향을 강조합니다. 반면에 신흥 시장 기업에 대한 연구는 비즈니스 성과에 대한 관련 다각화 (related diversification)의 긍정적인 영향을 강조합니다. 그러나 기업은 관련 다각화 (related diversification) 및 비관련 다각화 (unrelated diversification) 모두에서 이익을 얻을 수 있습니다. 따라서 중요한 것은 다각화하는 산업이 아니라 다양한 분야에서 어떻게 시너지를 낼 수 있는지 입니다. 이는 다각화 전략을 종합적으로 설명하기 위해서는 “what” 접근법 뿐만 아니라 “How” 접근법도 중요하다는 문 교수님의 ABCD 모델 이론과 일맥상통합니다. 자원과 기술 보유의 격차가 좁혀지고 기업들이 비슷한 수준의 자원을 갖게 되었기 때문에 최근에는 “How” 접근법이 특히 중요합니다. 기업의 성과에 대한 다각화 (diversification) 효과에 대한 더 나은 이해를 달성하기 위해, 본 논문은 다각화가 수행되는 방식과 프로세스를 통해 이해되어야 함을 강조합니다. 본 연구는 ABCD 모델의 융합 (convergence) 방법론과 전략경영 분야의 다각화 분야의 공백을 메워줄 시너지 창출의 4가지 조건을 활용하였습니다. 본 논문은 삼성전자를 사례연구로 분석하고, 삼성전자의 다각화가 스마트폰 산업의 성공에 어떻게 기여했는지 설명하는 융합 방법론의 적용 가능성을 보여주고 있습니다. 본 연구는 삼성이 혼합 다각화 (combined diversification)의 형태, 즉 관련되거나 관련이 없는 것처럼 보이는 다각화 모두를 적용했음을 보입니다. 계열사들은 부문 간 자원과 노하우를 공유하므로 잠재적 비용을 줄이는 호환성이 매우 높습니다. 그들의 강점과 약점은 지속적인 사업 구조 조정과 교차 투자로 인해 상호 보완적입니다. 각 회사는 서로 다른 활동의 운영을 연결하는 견고한 네트워크 시스템에 속해 보호를 받습니다. 마지막으로, 그들은 단독으로 운영하는 경쟁사들에 비해 월등한 상업적 가치를 제공할 수 있는 강력한 파트너십을 보여줍니다. 앞으로 삼성전자가 경쟁력을 유지하려면 다양한 부문의 접점을 개선해야 합니다. 사업 부문에서 나오는 강점과 약점의 보완성을 강화하는 것이 특히 기본이 될 것입니다. 융합 (convergence) 방법론을 통해 적용된 “how” 방법론은 유사한 자원 수준을 가진 상황의 기업집단들을 종합적으로 분석하는 가장 좋은 방법임이 이론적 관점에서 입증되었습니다.The literature on firm diversification from advanced countries emphasizes the benefits of related diversification and its positive impacts on firm performance. On the other hand, studies on firms from emerging markets highlight the positive influences of unrelated diversification on business performance. However, firms can benefit from both related and unrelated diversification. Therefore, what is important is not the industries in which diversifying, but how synergies can be created among various sectors. This is consistent with Moon’s argument of the ABCD model, that not only “what” factors but also “how” factors are important to comprehensively explain diversification strategies. How factors are particularly critical in recent times since the gap in resources and technology endowment narrows and firms find themselves with similar levels of resources. In order to achieve a better understanding of diversification effects on firm’s performance, this paper highlights that diversification should be comprehended through the ways and processes it is performed. This study uses the ABCD model’s convergence factor and the four conditions for synergy-creation filling the void in the diversification branch of the strategic management field. This paper analyses Samsung Electronics as a case study and shows the applicability of the convergence factor in explaining how Samsung’s diversification contributed to its success in the smartphone industry. This research finds that Samsung adopted a form of combined diversification hence, both related and seemingly unrelated diversification. The member companies are highly compatible since they share resources and know-how among sectors reducing potential costs. Their strengths and weaknesses are complementary thanks to continuous business restructuring and cross-investments. Each company is supported by a solid network system connecting different activities’ operations. Finally, they show strong partnerships which can deliver superior commercial value in comparison with stand-alone competitors. Going forward, to sustain its competitiveness, Samsung Electronics will need to improve the convergence of different segments. It will be especially fundamental to enhance the complementarity of strengths and weaknesses coming from its business segments. From the theoretical perspective, the how approach, applied through the convergence factor, proved to be the best method to comprehensively analyze business groups in an era in which there are similar resource levels.I. Introduction 1 II. Literature Review 4 2.1 Diversification Purpose 4 2.2 Related, Unrelated or Both Combined? 5 2.3 Diversification in Developed and Developing Countries 7 2.3.1 Highly Industrialized Context 8 2.3.2 Late Industrializing Context 9 2.4 A New Dynamic Approach to Competitiveness 10 2.5 Theoretical Background 11 III. Methodology 14 IV. A Case Study of Samsung Electronics 16 4.1 Company Profile 16 4.2 Previous Studies on Samsung Electronics 19 4.3 Convergence of Samsung Electronics 20 4.3.1 Compatibility of Member Companies’ Strengths 20 4.3.2 Complementarity of Member Companies’ Strengths and Weaknesses 24 4.3.3 A Solid Network System Supporting Various Activities’ Operations 27 4.3.4 Partnership’s Superior Commercial Value Against Standalone Competitors 29 V. Results 32 VI. Conclusion 37 References 42 Appendix 1 Articles and Books Regarding Positive Diversification Effects on Firm Performance 52 Appendix 2 Samsung Electronics Business Composition as of 2019 56 국문 초록 57석

Unmanned Aerial Vehicle Forensic Investigation Process: Dji Phantom 3 Drone As A Case Study

Drones (also known as Unmanned Aerial Vehicles, UAVs) is a potential source of evidence in a digital investigation, partly due to their increasing popularity in our society. However, existing UAV/drone forensics generally rely on conventional digital forensic investigation guidelines such as those of ACPO and NIST, which may not be entirely fit_for_purpose. In this paper, we identify the challenges associated with UAV/drone forensics. We then explore and evaluate existing forensic guidelines, in terms of their effectiveness for UAV/drone forensic investigations. Next, we present our set of guidelines for UAV/drone investigations. Finally, we demonstrate how the proposed guidelines can be used to guide a drone forensic investigation using the DJI Phantom 3 drone as a case study

Nanoscale resistive switching memory devices: a review

In this review the different concepts of nanoscale resistive switching memory devices are described and classified according to their I–V behaviour and the underlying physical switching mechanisms. By means of the most important representative devices, the current state of electrical performance characteristics is illuminated in-depth. Moreover, the ability of resistive switching devices to be integrated into state-of-the-art CMOS circuits under the additional consideration with a suitable selector device for memory array operation is assessed. From this analysis, and by factoring in the maturity of the different concepts, a ranking methodology for application of the nanoscale resistive switching memory devices in the memory landscape is derived. Finally, the suitability of the different device concepts for beyond pure memory applications, such as brain inspired and neuromorphic computational or logic in memory applications that strive to overcome the vanNeumann bottleneck, is discussed

Low-complexity algorithms for automatic detection of sleep stages and events for use in wearable EEG systems

Objective: Diagnosis of sleep disorders is an expensive procedure that requires performing a sleep study, known as polysomnography (PSG), in a controlled environment. This study monitors the neural, eye and muscle activity of a patient using electroencephalogram (EEG), electrooculogram (EOG) and electromyogram (EMG) signals which are then scored in to different sleep stages. Home PSG is often cited as an alternative of clinical PSG to make it more accessible, however it still requires patients to use a cumbersome system with multiple recording channels that need to be precisely placed. This thesis proposes a wearable sleep staging system using a single channel of EEG. For realisation of such a system, this thesis presents novel features for REM sleep detection from EEG (normally detected using EMG/EOG), a low-complexity automatic sleep staging algorithm using a single EEG channel and its complete integrated circuit implementation. Methods: The difference between Spectral Edge Frequencies (SEF) at 95% and 50% in the 8-16 Hz frequency band is shown to have high discriminatory ability for detecting REM sleep stages. This feature, together with other spectral features from single-channel EEG are used with a set of decision trees controlled by a state machine for classification. The hardware for the complete algorithm is designed using low-power techniques and implemented on chip using 0.18μm process node technology. Results: The use of SEF features from one channel of EEG resulted in 83% of REM sleep epochs being correctly detected. The automatic sleep staging algorithm, based on contextually aware decision trees, resulted in an accuracy of up to 79% on a large dataset. Its hardware implementation, which is also the very first complete circuit level implementation of any sleep staging algorithm, resulted in an accuracy of 98.7% with great potential for use in fully wearable sleep systems.Open Acces

Special Topics in Information Technology

This open access book presents thirteen outstanding doctoral dissertations in Information Technology from the Department of Electronics, Information and Bioengineering, Politecnico di Milano, Italy. Information Technology has always been highly interdisciplinary, as many aspects have to be considered in IT systems. The doctoral studies program in IT at Politecnico di Milano emphasizes this interdisciplinary nature, which is becoming more and more important in recent technological advances, in collaborative projects, and in the education of young researchers. Accordingly, the focus of advanced research is on pursuing a rigorous approach to specific research topics starting from a broad background in various areas of Information Technology, especially Computer Science and Engineering, Electronics, Systems and Control, and Telecommunications. Each year, more than 50 PhDs graduate from the program. This book gathers the outcomes of the thirteen best theses defended in 2020-21 and selected for the IT PhD Award. Each of the authors provides a chapter summarizing his/her findings, including an introduction, description of methods, main achievements and future work on the topic. Hence, the book provides a cutting-edge overview of the latest research trends in Information Technology at Politecnico di Milano, presented in an easy-to-read format that will also appeal to non-specialists

Acquisition and Analysis of Digital Evidencein Android Smartphones

From an expert's standpoint, an Android phone is a large data repositorythat can be stored either locally or remotely. Besides, its platform allows analysts toacquire device data and evidence, collecting information about its owner and facts underinvestigation. This way, by means of exploring and cross referencing that rich data source,one can get information related to unlawful acts and its perpetrator. There are widespreadand well documented approaches to forensic examining mobile devices and computers.Nevertheless, they are neither specific nor detailed enough to be conducted on Androidcell phones. These approaches are not totally adequate to examine modern smartphones,since these devices have internal memories whose removal or mirroring procedures areconsidered invasive and complex, due to difficulties in having direct hardware access. Theexam and analysis are not supported by forensic tools when having to deal with specific filesystems, such as YAFFS2 (Yet Another Flash File System). Furthermore, specific featuresof each smartphone platform have to be considered prior to acquiring and analyzing itsdata. In order to deal with those challenges, this paper proposes a method to perform dataacquisition and analysis of Android smartphones, regardless of version and manufacturer.The proposed approach takes into account existing techniques of computer and cellphone forensic examination, adapting them to specific Android characteristics, its datastorage structure, popular applications and the conditions under which the device wassent to the forensic examiner. The method was defined in a broad manner, not namingspecific tools or techniques. Then, it was deployed into the examination of six Androidsmartphones, which addressed different scenarios that an analyst might face, and wasvalidated to perform an entire evidence acquisition and analysis

Mobile Forensics – The File Format Handbook

This open access book summarizes knowledge about several file systems and file formats commonly used in mobile devices. In addition to the fundamental description of the formats, there are hints about the forensic value of possible artefacts, along with an outline of tools that can decode the relevant data. The book is organized into two distinct parts: Part I describes several different file systems that are commonly used in mobile devices. · APFS is the file system that is used in all modern Apple devices including iPhones, iPads, and even Apple Computers, like the MacBook series. · Ext4 is very common in Android devices and is the successor of the Ext2 and Ext3 file systems that were commonly used on Linux-based computers. · The Flash-Friendly File System (F2FS) is a Linux system designed explicitly for NAND Flash memory, common in removable storage devices and mobile devices, which Samsung Electronics developed in 2012. · The QNX6 file system is present in Smartphones delivered by Blackberry (e.g. devices that are using Blackberry 10) and modern vehicle infotainment systems that use QNX as their operating system. Part II describes five different file formats that are commonly used on mobile devices. · SQLite is nearly omnipresent in mobile devices with an overwhelming majority of all mobile applications storing their data in such databases. · The second leading file format in the mobile world are Property Lists, which are predominantly found on Apple devices. · Java Serialization is a popular technique for storing object states in the Java programming language. Mobile application (app) developers very often resort to this technique to make their application state persistent. · The Realm database format has emerged over recent years as a possible successor to the now ageing SQLite format and has begun to appear as part of some modern applications on mobile devices. · Protocol Buffers provide a format for taking compiled data and serializing it by turning it into bytes represented in decimal values, which is a technique commonly used in mobile devices. The aim of this book is to act as a knowledge base and reference guide for digital forensic practitioners who need knowledge about a specific file system or file format. It is also hoped to provide useful insight and knowledge for students or other aspiring professionals who want to work within the field of digital forensics. The book is written with the assumption that the reader will have some existing knowledge and understanding about computers, mobile devices, file systems and file formats