京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第22809号 / 情博第739号 / 新制||情||126(附属図書館) / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 大木 英司, 教授 守倉 正博, 教授 原田 博司 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

The Scandinavian country of Sweden is a huge facilitator of startups through its’ large network of incubators where Born Global residents are becoming a more frequent sight. The Born Global firm is a novel type of company that contradicts the traditional means of internationalization. In order to realize startup potential, the obtainment of resources of varying amounts and scope is essential. But for a Born Global startup, achievement of its internationalization prospects requires making use of a unique set of resources that facilitate and enables the fulfillment of such global capabilities. The purpose of this paper is to identify the resources that are crucial for a Born Global in an internationalization context and whether or not Swedish incubators can provide these crucial resources to Born Globals. The analysis is based on the findings from semi-structured interviews with members from 3 Incubators and 4 Born Global companies in the incubation process within their respective incubators. Using a comparative study, alignments and gaps have been identified between what incubators have provided and what Born Globals consider crucial for internationalization. The conclusion of this study leads to an addition to the theory of the Incubator Best Practice Model, elaborated by Bergek and Norrman where the facilitation of the unique resources required by Born Global companies is emphasized. Additionally, the authors provide suggestions on managerial implementations for Born Global managers. These suggestions concern thorough assessments of their individual resource needs, and policy recommendations to incubators about the facilitation of the specific resources required for a Born Global and its effort to internationalize.

The research explores the competencies that lead to firm success, success defined as the attainment of above-average rents over the long-term. The research asserts that to fully understand how companies come to be successful one needs to adopt a complex understanding of performance led by the internal workings of the firm. This involves identifying how different allocation processes might adapt resources to develop unique organisational competencies.Case study research was the most appropriate methodology to use in studying the internal workings of the firm. The case study focused on a single South African firm and, more specifically, on the competencies within a particular business division. Five competencies were identified and their development and evolution analysed in five historical phases of the organisation.Key findings are summarised as follows: strong leadership was essential in driving a particular strategy that once it became institutionalised developed into a core competence; one of the precursors to the development of competencies was the leaders’ choice of the firm’s positioning on the value chain; a collaborative organisational structure was not necessary for the development or evolution of organisational competencies; external sourcing for competencies was unsuccessful when the acquired competencies were foreign to the existing store of competencies in the organisation; institutionalisation, initially required to develop certain competencies, can inert the evolution of competencies due to perceived threats to existing norms and values in the organisation. The research also explored the development of competencies in an isolated environment which affords time to allocate resources and to develop processes in isolation from external market forces to build unique competencies.The findings contribute to an in-depth understanding of the reasons for the firm’s success as well as contributing to an area of strategy theory that is empirically understudied, particularly in the South African case. The research concludes with suggestions for further research to contribute to this important understudied area. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

Cette thèse examine la façon dont les choix stratégique des firmes multi-établissements affectent la performance de leurs filiales et contribuent aux débats récurrents liés à la pertinence et l’importance de la stratégie d’entreprise. Dans le premier chapitre, nous nous intéressons à savoir le poids relatif des décisions stratégiques des sièges sociaux sur la performance de leurs établissements. Nous montrons l’incapacité des méthodes traditionnelles à rendre compte efficacement des effets entreprises. Nous soutenons en effet que les études précédentes sous-estiment systématiquement les effets entreprises car elles ne tiennent pas compte de l’hétérogénéité de l’impact des décisions des sièges sociaux sur leurs filiales. Une filiale peut recevoir une part très différente des ressources de l’entreprise. Par conséquent, le fait d’étudier toutes les filiales comme s’il s’agissait d’un seul groupe sous-estime systématiquement les effets entrepris. Nous soutenons plutôt qu’il est important de tenir compte de la variance induite par l’entreprise sur la performance des filiales. Nous appelons cette variance induite « effet entreprise variant », et montrons qu’elle est tout aussi importante que la valeur des effets entreprise standards, à savoir « les effets entreprise invariants ». Dans le deuxième chapitre nous nous sommes intéressés au débat relatif à l’efficacité des marchés de capitaux internes, comme une des sources essentielles d’hétérogénéité de la performance des filiales. La question centrale du débat consiste à discuter les modalités d’allocation optimale du capital. Les études empiriques mettent en évidence des montants d’allocation très au-dessus des niveaux optimaux dans des filiales qui ont des niveaux de croissance apparemment relativement faibles. Tenant compte à la fois du degré d’incertitude auquel une firme est confrontée lorsqu’elle décide d’allouer son capital et du niveau d’interdépendance de ses filiales, nous distinguons « les déviations inefficaces » des « déviations non nécessairement inefficaces ». Nous expliquons que les déviations par rapport à la logique de sélection des gagnants dans les décisions d’allocation de capital peuvent simplement refléter des intentions stratégiques différentes plutôt que des inefficacités d’allocation. De plus, nous soulignons le rôle de l’ampleur de l’expérience antérieure des dirigeants dans le domaine des filiales, en tant que source de compétences en allocation de capital des firmes, dans l’atténuation des déviations inefficaces et l’augmentation de la valeur de la corporation grâce à de meilleures pratiques d’allocation du capital. Le troisième chapitre incorpore les ressources financières à la théorie de redéploiement des ressources. La théorie standard a exclu les ressources financières qui, par définition, peut être allouée et ré-allouées à tout type d’investissement sans contrainte. Nous soutenons toutefois que, lors de l’affectation vers l’une de ses filiales de ressources financières à des investissements imparfaitement fongibles ou divisibles, telles que le capital physique, tel que des usines ou des technologies, le siège social achète également l’option de redéploiement de ces mêmes ressources dans le futur. En effet, le choix d’investissement présent doit être réalisé en tenant compte des coûts de redéploiement éventuels dans le futur. Par conséquent, la direction des flux de capitaux actuels entre les filiales ne sera pas simplement réalisée en fonction des opportunités actuelles de croissance relative du marché, mais aussi en fonction des coûts d’ajustement due aux redéploiements éventuels entre les filiales dans les périodes ultérieures. Cette extension permet d’étendre le champ d’études empiriques de la théorie du redéploiement de ressources non-financier. En effet, les études empiriques dans ce domaine ont été rares jusqu'à présent en raison du défi que représentent l'observation et la mesure du redéploiement des ressources non financières. / This dissertation deals with how multi-business firms’ strategies affect the performance of subsidiary businesses and contributes to long standing debates in corporate strategy. Overall, each of my 3 dissertation essays are designed to, correspondingly, analyze the debated magnitude, efficiency, and mechanism of the effect of a multi-business firms’ strategies on the performance of its subsidiaries. In the first chapter, I address a root question in corporate level strategy; I question traditional methods to estimate corporate effects (the effect of corporate headquarters on subsidiary businesses’ performance). I argue that previous corporate effect studies fail to account for the uneven impact of corporate decisions on subsidiaries. A headquarters makes conscious and deliberate decisions that might induce performance heterogeneity among its subsidiaries. Consequently, considering all subsidiaries as a bundle will systematically underestimate the corporate effects. Rather, I argue that it is important to account for the firm’s induced variance on the subsidiaries’ performance. We connote this induced variance as “business-variant corporate effects”, and show that they are just as important in magnitude as the value of the standard corporate effects, namely “business-invariant corporate effects”, found in previous studies. In the second essay, I focus on corporate capital allocation as a critical dimension of corporate strategies that might contribute to, within-firm, subsidiaries’ performance heterogeneity. We particularly delve deeper into the internal capital market efficiency debate by extending current theories that aim to justify why headquarters provide more resources to subsidiaries with seemingly lower growth opportunities. Considering both the level of uncertainty a firm faces when making capital allocation decisions, and the level of interdependence among its subsidiaries, we disentangle between inefficient and not-necessarily-inefficient deviations from standard models’ prescription. We explain that higher investments in subsidiaries with seemingly lower growth opportunities may simply reflect different strategic intents rather than allocation inefficiencies. Furthermore, we highlight the role of the breadth of CEOs’ prior experience in subsidiaries’ domain, as a source of firms’ capital allocation competency, in attenuating inefficient deviations and enhancing corporate value through better capital allocation practices. In the third essay, I incorporate financial resources, as a perfectly fungible and divisible resource, within the scope of the resource redeployment theory. Indivisibility and imperfect fungibility of resources play a critical role in the theory and this is why the standard theory has excluded the financial resources from its boundaries. I, however, argue that when allocating financial resources, such as capital, to one of its subsidiaries to acquire non-financial assets such as plants or technology, a corporate headquarters also purchases the option to redeploy those same resources in subsequent periods. Therefore, the direction of current capital flow among subsidiary businesses will not merely be a function of their current relative market growth opportunities. Rather, it is a function of the adjustment costs of potential resource redeployments among the subsidiaries in subsequent periods. My extension of the resource redeployment theory to include intrafirm capital allocations paves the way for further empirical investigations of the theory; that have been scarce so far, due to the challenge of observing and measuring the redeployment of non-financial resources. In turn, studying intrafirm capital allocations through the lens of RR theory helps us further develop and offer novel predictions for the theory.

Millimeter wave (mmWave) plays a critical role in the Fifth-generation (5G) new radio due to the rich bandwidth it provides. However, one shortcoming of mmWave is the substantial path loss caused by poor diffraction at high frequencies, and consequently highly directional beams are applied to mitigate this problem. A typical way of beam management is to cluster users based on their locations. However, localization uncertainty is unavoidable due to measurement accuracy, system performance fluctuation, and so on. Meanwhile, the traffic demand may change dynamically in wireless environments, which increases the complexity of network management. Therefore, a scheme that can handle both the uncertainty of localization and dynamic radio resource allocation is required. Moreover, since the localization uncertainty will influence the network performance, more state-of-the-art localization methods, such as vision-aided localization, are expected to reduce the localization error. In this thesis, we proposed two algorithms for joint radio resource allocation and beam management in 5G mmWave networks, namely UK-means-based Clustering and Deep Reinforcement Learning-based resource allocation (UK-DRL) and UK-medoids-based Clustering and Deep Reinforcement Learning-based resource allocation (UKM-DRL). Specifically, we deploy UK-means and UK-medoids clustering method in UK-DRL and UKM-DRL, respectively, which is designed to handle the clustering under location uncertainties. Meanwhile, we apply Deep Reinforcement Learning (DRL) for intra-beam radio resource allocations in UK-DRL and UKM-DRL. Moreover, to improve the localization accuracy, we develop a vision-aided localization scheme, where pixel characteristics-based features are extracted from satellite images as additional input features for location prediction. The simulations show that UK-DRL and UKM-DRL successfully improve the network performance in data rate and delay than baseline algorithms. When the traffic load is 4 Mbps, UK-DRL has a 172.4\% improvement in sum rate and 64.1\% improvement in latency than K-means-based Clustering and Deep Reinforcement Learning-based resource allocation (K-DRL). UKM-DRL has 17.2\% higher throughput and 7.7\% lower latency than UK-DRL, and 231\% higher throughput and 55.8\% lower latency than K-DRL. On the other hand, the vision-aided localization scheme can significantly reduce the localization error from 17.11 meters to 3.6 meters.

This thesis presents three chapters. In Chapter 1, I propose a simple one-to-one matching model, where individuals on one side have private information that affects the preferences of the individuals on the other side. I show the existence of the stable and strategy-proof mechanism in this environment. I present an algorithm that defines this mechanism - the Serial Dictatorship algorithm with cutoffs. I also consider the concept of obvious strategy-proofness. I first consider the case where only preferences, but not experience levels, are sellers' private information. For this case, Serial Dictatorship with cutoffs elicits preferences in an obviously strategy-proof way. On the other hand, when only experience levels, but not preferences are private information, I show that there is no obviously strategy-proof and stable mechanism. A consequence of the latter result is that obvious strategy-proofness is incompatible with stability. Chapter 2 considers settings with rich private information - an agent's type may include private information other than just his preferences. In such settings, I identify a necessary condition for obviously strategy-proof implementation of social choice rules. I consider applications to strict preferences, matching and object allocation. The main assumption behind the obvious dominance is that agents might be cognitively limited and can not engage in contingent reasoning at all. This assumption is unreasonably weak compared to the standard assumption that agents can perfectly distinguish contingencies. In Chapter 3, I strengthen it slightly by assuming that agents are able to do at least some contingent reasoning. I define what it means for the strategy to be obviously dominant with respect to a partition of the state space. I call such strategies partition dominant strategies. A strategy is an almost obviously dominant if, for all possible partitions, but not for the coarsest, it can be identified as being partition dominant. My hypothesis is that even though some agents can not do state-by-state reasoning as rational players do, they are able to do at least some partitioning of the other player’s actions and regardless of how the partitioning is done, the agents can identify an almost obviously dominant strategy.

Following the rapid development of mobile infrastructure and hand-held user devices like smartphones and tablets, the way that mobile networks have been utilized has changed accordingly. Users are no longer using their phones just to talk to and message each other, but have migrated most of their multimedia consumption to these devices. The increased network strain and reduced profit margins that new services bring to the table might lead to future decoupling between revenues and expenses in the network. In order to avoid this scenario various different strategies have been proposed and one of them is introduction of QoS/QoE related resource allocation techniques. This thesis looks at Interruption Prediction scheduler which tries to predict and prevent audio or video interruptions experienced during video conference call. In order to test the performance of these schedulers, MATLAB simulator reusing some of the functions from RUNE toolbox has been used. Results of the newly presented algorithms are compared with a QoE/QoS agnostic scheduler. Unfortunately results of these schedulers in the case of video conference are not as promising as they were in the case of some other types of services. The research done shows that these modifications of the scheduling algorithms do not help to increase the network performance in terms of observed KPIs (Total Time of Interruptions, Frequency of Interruptions and network throughput) in most of the described scenarios. However, there are some special scenarios when these schedulers show a certain potential.

In the last decade, data networks have shifted from the static deployment of resources to a dynamic approach. With the help of Software Defined Networks (SDN) and Network Function Visualization (NFV), information and data about the network can be collected. Also, deployment and allocation of resources can be delegated to a central controller. In this thesis we investigate the power of SDN and how central management of resources can help produce better and efficient data networks. It begins with an introduction to SDN and its capabilities. The added benefits of SDN over traditional network frameworks and topics that SDN contributed most to. We show the power of collecting data using SDN and how it enables different approaches to accomplish the needed task. This was facilitated by the programmability and the separation of the control and data planes. We tackle the simple task of measuring the delay between two communicating devices in the network. The results show that SDN is capable of providing a rich infrastructure to build future networks. Also, it illustrates that using SDN to measure the delay between devices in the network can give accurate results. The differences between the tested techniques is shown and evaluated. After collecting the data from the network, the next step is getting an insight on that data. Next we used collected network bandwidth data to predict future bandwidth usage. We used various prediction models to establish prediction intervals. We created a state of the art metric that evaluates and compares the performance of each model. We show that the network bandwidth is highly predictable and that dynamic allocation of network bandwidth is attainable. The next logical step is to act upon those insight which is investigated next. We establish the same prediction models investigated but instead of prediction intervals we establish upper quantiles. Prediction is done on data center resources data set. The results show that using quantile prediction can give guarantees on resources usage boundaries which implies a guarantee on service level agreements. Allocating just the needed resources, produce a more efficient data center and in turn cuts a lot of the needed energy. Our estimate show that upto 56% of power can be saved without violating the service level agreement. / Graduate

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Cognitive radios is one of the hot topics for emerging and future wireless commu- nication. It has been proposed as a suitable solution for the spectrum scarcity caused by the increase in frequency demand. The concept is based on allowing unlicensed users, called cognitive or secondary users, to share the unoccupied frequency bands with their owners, called the primary users, under constraints on the interference they cause to them. The objective of our work is to propose some enhancements to cognitive radio systems while taking into account practical constraints. Cogni- tive radios requires a capability to detect spectrum holes (spectrum sensing) and a scheduling flexibility to avoid the occupied spectrum and selectively use the empty spectrum (dynamic resource allocation). Thus, the work is composed of two main parts. The first part focuses on cooperative spectrum sensing. We compute in this part the analytical performance of cooperative spectrum sensing under non identical and imperfect channels. Different schemes are considered for the cooperation between users such as hard binary, censored information, quantized, and soft information. The second part focuses on the dynamic resource allocation. We first propose low-cost re- source allocation algorithms that use location information to estimate the interference to primary users to replace absence of instantaneous channel state information. We extend these algorithms to handle practical implementation constraints such as dis- 5 crete bit-loading and collocated subcarriers allocations. We then propose a reduced dimension approach based on the grouping of subcarriers into clusters and performing the resource allocation over clusters of subcarriers instead of single subcarriers. This approach is shown to reduce the computational complexity of the algorithm with lim- ited performance loss. In addition, it is valid for a generic set of resource allocation problems in presence of co-channel interference between users.