<p dir="ltr">Upon acquiring or learning another language, cross-linguistic influence (CLI) is an inevitable phenomenon with which a bilingual speaker lives. One key aspect of CLI is its bidirectionality, flowing between both the first (L1) and second languages (L2) mutually affecting each other. However, investigations of L1 CLI on L2 have dominated previous bilingual studies, and despite the increasing amount of research on L2 CLI on L1, the phonetic and phonological domains remain relatively underexplored. The primary goal of the present study is to expand our understanding of the underlying mechanisms governing L2 CLI on L1 phonetics and phonology.</p><p dir="ltr">The present study investigates L2 CLI on L1 phonetics and phonology by examining both the speech perception and production of L1 sound categories among two different groups of bilinguals, Korean heritage speakers (HSs, <i>n</i> = 30) and long-term immigrants (LTIs, <i>n</i> = 27) group participants in the US, in comparison to L1(Korean)-immersed (L1-i) native speakers residing in South Korea (<i>n</i> = 30). Participants completed a series of three experimental tasks: (1) a three-alternative forced-choice (3AFC) identification task, (2) an AX discrimination task, and (3) a controlled reading paradigm task.</p><p dir="ltr">Experiment 1 (3AFC task) was conducted to investigate the extent and direction of L2 CLI in perceptual cue weighting to L1 speech categories. In this task, participants listened to a Korean word in each trial, potentially differing in the word-initial stop, and decided which word they heard from a real-word Korean minimal triplet /pul/ ‘fire,’ /p^hul/ ‘grass,’ and /p^*ul/ ‘horn.’ Specifically, the word-initial stop consisted of an eight-by-eight orthogonal voice onset time (VOT)–onset f0 continuum, created through a speech resynthesis technique. Based on the similarities and differences in the use of the two acoustic parameters between Korean (either onset f0 or VOT is a primary cue) and English stops (VOT is the primary cue), bilingual participants were expected to exhibit different cue-weighting patterns, as compared to L1-i speakers. The results from the mixed-effects logistic regression model analyses indicated that while HSs were less sensitive to the Korean primary cue, onset f0, compared to L1-i speakers—suggesting assimilation to L2 in the perceptual domain—LTIs exhibited greater sensitivity to this cue, indicating dissimilation from L2. It was also found that bilingual participants’ Korean dominance significantly influenced their cue weighting in the perception of Korean stops.</p><p dir="ltr">Experiment 2 (AX discrimination task) was administered to assess participants’ perceptual accuracy for L1 stop categories and the potential impact of L1 cue weighting, as estimated in Experiment 1, on their discrimination performance. Notably, the VOT in the stop stimuli used in the AX task were resynthesized to have a consistent VOT of 70 ms across all stimuli. This setup created a condition where participants had no choice but to rely solely on the onset f0 cue—the primary cue to the Korean lenis-aspirated stop contrast, rendering VOT, the primary cue for the voicing contrast in English stops, uninformative. The results from mixed-effects logistic regression models showed that HSs were significantly less accurate in discriminating their L1 stop categories without the VOT cue, while LTIs outperformed the L1-i speakers. That is, the LTI group, the most balanced group in terms of language dominance, had the highest accuracy in discriminating L1 contrasts among the participant groups. Furthermore, individual sensitivity to the onset f0 cue was found to be positively correlated with discrimination performance.</p><p dir="ltr">Experiment 3 (Controlled reading paradigm) aimed to examine L2 CLI on the implementation of acoustic parameters for L1 Korean stops, as well as the potential impact of proficiency and dominance on these parameters. Participants read aloud a list of minimal triplet stimuli differing in the word-initial stop within a carrier phrase. A machine-learning-based audio signal detection system was used to analyze the acoustic parameters, and Bayesian mixed-effects linear regression models, along with quadratic polynomial regression models, were implemented for statistical analysis of the processed data. The results of the production task mirrored the perception task (Experiment 1): HSs demonstrated assimilation to L2 via onset f0, while LTIs showed dissimilation, as compared to L1-i speakers. The analysis also revealed that the degree of bilingual balance in dominance and proficiency significantly influenced the implementation of onset f0, with more balanced bilinguals exhibiting greater category contrasts than less balanced bilinguals, regardless of whether they were Korean-dominant or English-dominant.</p><p dir="ltr">The findings from these experiments provide concrete evidence of L2 CLI in L1 phonetics and phonology. Importantly, the results demonstrate that not only the timing of L2 acquisition and the quantity and quality of L2 input but also the quality and quantity of L1 acquisition and bilingual balance contribute to the direction and the degree of L2 CLI in L1 speech. These findings align with the predictions of the revised Speech Learning Model (SLM-r, Flege & Bohn, 2021) and expand its scope of application to include both HSs and LTIs. In particular, the evidence of category assimilation and dissimilation lends support to the bidirectional CLI hypothesis proposed by SLM-r. To conclude, the present dissertation expands our understanding of the nature of L2 CLI in L1 phonetics and phonology in bilingual speakers.</p>

Additive manufacturing of Nitinol is a promising field, as it can circumvent the challenges associated with its conventional production processes and unlock unique advantages. However, the accompanying surface features such as powder adhesions, spatters, ballings, or oxide discolorations are undesirable in engineering applications and therefore must be removed. Plasma electrolytic polishing (PeP) might prove to be a suitable finishing process for this purpose, but the effects of post-processing on the mechanical and functional material properties of additively manufactured Nitinol are still largely unresearched. This study seeks to address this issue. The changes on and in the part caused by PeP with processing times between 2 and 20 min are investigated using Nitinol compression springs manufactured by Laser Beam Melting. As a benchmark for the scanning electron microscope images, the differential scanning calorimetry (DSC) measurements, and the mechanical load test cycles, conventionally fabricated Nitinol springs of identical geometry with a medical grade polished surface are used. After 5 min of PeP, a glossy surface free of powder adhesion is achieved, which is increasingly levelled by further polishing. The shape memory properties of the material are retained without a shift in the transformation temperatures being detectable. The decreasing spring rate is primarily attributable to a reduction in the effective wire diameter. Consequently, PeP has proven to be an applicable and effective post-processing method for additively manufactured Nitinol.

Land degradation is a great threat to the Beshlo Catchment in Blue Nile Basisn, not merely as an environmental issue, but also a social and economic problem. In Gedalas Watershed (one of the micro catchments of Beshelo), land degradation, mediated by both biophysical and socio-economic drivers, is among the major environmental sustainability and social-economic development threats in the area. The threat is manifested in depletion of natural vegetations, water, soil and other natural resources; disruption of ecosystem functions, processes, integrity, and services. Given its particular vulnerability, watershed management activities have been in operation since the mid-1970s. Recently, the idea of Sustainable land management through integrated watershed development program has been initiated with the objective of reducing land degradation risks and ensuring food security at both the nationwide and family circle. Despite these investments and efforts, real evidences of success and failures of such efforts were not satisfactory explored. The objectives of this study were, therefore, to analyze the existing status and future prospects of sustainable land management and evaluates its implication on the environmental integrities and the local livelihoods specific to Gedalas watershed. For this effect, the study investigated the dynamics, deriving forces and implications of LULC, soil erosion and soil fertility status of the watershed, current status of watershed management practices, pertinent challenges and opportunities for practicing land management technologies and approaches that might help meet the sustainability requirements of SLM practices. In addition, the study explored factors that determine the willingness of farming households to undertake SLM practice. As the study carried in the coupled human-environment system of rural landscapes, interdisciplinary geographical approaches which integrats social and natural science methodologies were employed to deal with issues of land degradation-and-rehabilitation status comprehensively. The general findings of the study show that though it would be dificult to measure all the composite aspects of land degradation, some of the parameters considered in this study revealed that land degradation is a perpetuating challenge in the watershed. It is evidenced from the overall undesirable land use/cover changes i.e transition of 21.25% of Afro/sub alpine landscapes, 17.59% of the grasslands and 8% of shrub lands to either to cultivated land or settlement areas over the 1973–2017 period, which have unintended negative socio-ecological repercussions on the watershed; high annual mean soil loss value (which range from 37t/ha/year average values to 393 t/ha/yr soil loss rates on water courses) that exceed threshold level and a wide gap between the need for SLM and the actual achievement of SLM practices,including limited adherence to the idea behind contemporary land management policies and implementation principles and approaches. The study further revealed the presence of opportunities as well as a myriad of challenges that need to be tackled in order to achieve sustainable land management goals. The study colcludes that, though, some encouraging progresses have been observed in the SLM project sites; land degradation has remained a problem in the watershed. This calls for strenuous efforts to promote and assist wide scale adoption of SLM practices that address the pervasive land degradation problem and achieve land degradation neutrality as highlighted in sustainable development goals. / Department of Geography / Ph. D. (Geography)

This project was conducted as a case study at Öhlins Racing AB, a manufacturer of suspension systems for automotive applications. Öhlins usually manufacture their components by traditional methods such as forging, casting, and machining. The project aimed to investigate how applicable Additive Manufacturing (AM) is to manufacture products for suspension systems to add value to suspension system components. For this, a proof of concept was designed and manufactured. The thesis was conducted at Öhlins in Upplands Väsby via the consultant firm Combitech.  A product catalog was searched, screened, and one part was selected. The selected part was used as a benchmark when a new part was designed for AM, using methods including Topology Optimization (TO) and Design for Additive Manufacturing (DfAM). Product requirements for the chosen part were to reduce weight, add functions, or add value in other ways.  Methods used throughout the project were based on traditional product development and DfAM, and consisted of three steps: Product Screening, Concept Development, and Part Design. The re-designed part is ready to be manufactured in titanium by L-PBF at Amexci in Karlskoga.  The thesis result shows that at least one of Öhlin's components in their product portfolio is suitable to be chosen, re-designed, and manufactured by AM. It is also shown that value can be added to the product by increased performance, in this case mainly by weight reduction. The finished product is a fork bottom, designed with hollow structures, and is ready to print by L-PBF in a titanium alloy.

Das Anwendungsfeld der Luft- und Raumfahrtindustrie kennzeichnet sich durch eine konstante Nachfrage nach Materialien mit einer hohen spezifischen Festigkeit. Die metastabile Beta-Titanlegierung Ti-5553 ist ein aussichtsreicher Werkstoffkandidat, um der Forderung nach geringer Dichte bei gleichzeitig hoher Festigkeit gerecht zu werden. Bereits jetzt findet er Anwendung in strukturell-belasteten Bereichen. Der Herstellungsprozess für die dafür verwendeten Bauteile ist charakterisiert durch einen oftmals materialintensiven Zerspanungsprozess zur Erzeugung der gewünschten Geometrie und eine mehrstufige und zeitintensive Wärmebehandlung zur Einstellung des gewünschten Gefüges sowie den damit verbundenen Eigenschaften. Durch den Einsatz des selektiven Laserschmelzens (SLM) als Vertreter der additiven Fertigungsverfahren sollen diese zwei Problemstellungen adressiert werden. Einerseits wäre es möglich, durch den schichtweisen Aufbau der Bauteile, komplexe Geometrien endkonturnah zu fertigen und damit den Zerspanungsprozess zu minimieren. Andererseits können durch die im SLM-Prozess auftretenden hohen Erstarrungsraten metastabile Gefügezustände geschaffen werden. Daher besteht großes Interesse daran, die Verknüpfung von Prozessbedingungen und dem entstehenden Gefüge zu untersuchen und zu verstehen. Das Prozessieren und Optimieren der Legierung Ti-5553 auf das Verfahren des selektiven Laserschmelzens stellen den Ausgangspunkt dieser Arbeit dar. Durch die anschließende Variation der Belichtungsstrategie beziehungsweise der Anwendung einer Substratheizung konnten Korngröße sowie Textur respektive Phasenbildung im Gefüge beeinflusst werden. Somit war es möglich das Potenzial des selektiven Laserschmelzens aufzuzeigen, indem durch Prozessparameter Bauteileigenschaften während des Herstellungsprozesses aktiv beeinflusst werden. Die Analyse der hergestellten Proben umfasste eine tief greifende Gefügeanalyse sowie die Untersuchung der mechanischen Eigenschaften.

In the rapidly advancing field of artificial intelligence, Large Language Models (LLMs) like GPT-3, GPT-4, and Gemini have revolutionized sectors by automating complex tasks. Despite their advancements, LLMs and more noticeably smaller language models (SLMs) still face challenges, such as generating unfounded content "hallucinations." This project aims to enhance SLMs for broader accessibility without extensive computational infrastructure. By supervised fine-tuning of smaller models with new datasets, SQUAD-ei and SQUAD-GPT, the resulting model, KERMIT-7B, achieved superior performance in TYDIQA-GoldP, demonstrating improved information extraction while retaining generative quality. / Inom det snabbt växande området artificiell intelligens har stora språkmodeller (LLM) som GPT-3, GPT-4 och Gemini revolutionerat sektorer genom att automatisera komplexa uppgifter. Trots sina framsteg stårdessa modeller, framför allt mindre språkmodeller (SLMs) fortfarande inför utmaningar, till exempel attgenerera ogrundat innehåll "hallucinationer". Denna studie syftar till att förbättra SLMs för bredare till-gänglighet utan krävande infrastruktur. Genom supervised fine-tuning av mindre modeller med nya data-set, SQUAD-ei och SQUAD-GPT, uppnådde den resulterande modellen, KERMIT-7B, överlägsen pre-standa i TYDIQA-GoldP, vilket visar förbättrad informationsutvinning samtidigt som den generativa kva-liteten bibehålls.

隨著主管機關對金融商品規定的鬆綁，金融機構業務型態的變化越來越多，量也越來越大，對資訊系統依賴的程度也越來越高。其中，證券公司業務的執行及對客戶的服務，更是高度依賴IT服務的可用性、可靠性、安全性和表現的效能。然而，IT與業務部門需求認知上的落差及IT部門在企業內扮演角色認知上的錯誤及不當的IT管理方式，反而讓問題的發生層出不窮，IT也經常落入問題處理的深淵。 問題的複雜度雖然不斷提高，相對於業務單位對系統穩定性的要求卻更高。問題是：企業不可能因為追求效率上的完美而不斷花錢投入IT資源。在IT資源有限的情況下，IT部門須對這些問題，進行更有效的管理及回應。因此，IT治理不僅已成為金融機構實現業務目標的基本要素，也是獲取客戶信任不可或缺的元素。本論文則嘗試透過導入行之有年的ITIL管理方法，協助解決證券公司資訊部門的困境。 為能達到良好的IT服務治理結果，本研究針對業務單位對IT部門所提供的資訊服務期望，透過ITIL的服務水準管理流程（Service Level Management，SLM）來加以定義及描述。主要做法： 1.利用ITIL流程改善模型（Process Improvement Model）的四階段步驟，參考營業服務管理（Business Service Management，BSM）的觀念與做法，讓IT單位與業務部門能有更好的溝通。 2.依據溝通的結果產出實際可行之服務水準協議。簡言之，即是由使用者的角度去找出所需達到的IT服務標準。還可依此畫出營業服務與IT服務間之對應關係，明確彼此的責任。 3.透過重複不斷的檢討與回饋，讓IT服務能越來越符合實際業務的需要。 本研究發現，透過案例「致富快手」系統在服務水準管理流程中所獲得的業務單位對IT部門的服務期望資訊，對照現況IT部門的服務表現與目標水準的差異分析。的確可以協助IT部門就資訊服務的提供現況來推導，以獲致未來可進行服務改善的目標項目。而不再是以個人的直覺來進行系統維護與IT投資，這些效益還包括： 1.增進IT了解自己在企業營運上的價值貢獻；體會與業務單位的分工合作關係，減輕彼此的對立。 2.營業服務關鍵流程協助IT部門進行資源佈署，優化IT投資。 3.對營業服務關鍵流程，提供一具體、可量化的衡量標準與描述。可依此建立SLA與OLA。 4.服務期望與服務現況比較，了解IT服務對營業服務支持程度。 5.服務期望與服務現況差異化分析，為日後服務改善之依據。 6.營業服務與IT資源對應，明確IT資源關鍵元件；為備援建置及容量管理之重點對象。 7.以Business/IT知識庫檢視監控機制涵蓋程度，做為服務改善之目標。 8.透明IT營業支援服務體系，增進雙方溝通與問題處理有效性。 研究中也發現，服務水準管理流程只是在規範IT服務相關單位的行為活動。也就是說，服務水準管理流程其實只是在訂定IT服務的目標，至於應如何來實現，仍須藉由其他服務提供(Service Support)流程的有效支持；改善的具體實現，又會反應在服務水準指標的執行結果上，兩者其實為互相呼應，相輔相成的因果關係。 / As the finance production deregulates, the financial institutions could run more and more various businesses. In order to offer quality service, it’s necessary to have IT support in the back. So does Security Corporation. The business performances of a security corporation almost depend on an available, reliable, and secure IT services. However, there are some problems occurred between the business and IT units. In one hand, they both have misunderstanding in cognition to the other party; on the other hand, passive attitude and ineffective management of IT department made two groups always unsatisfied to each other. Furthermore, the spending of IT investment in a company is limited, but the business units continually require of better performance requirement. The atmosphere between two parties is in tension. For solving those problems, the study of IT governance comes out. It helps organization offer better IT service under limited resources. Moreover, IT governance is not only the effective method to realize business object, but the important one to obtain the customers’ trust. As the result, we use one of IT governance methodology, ITIL (IT Infrastructure Library), to resolve the predicament of IT department in the security corporation. In this paper, we identify the expectation to IT service from Business units using the concept of SLM (Service Level Management) module described in ITIL. Our analysis steps are as follow: I.Understand the needs: We use the “Process Improvement Model” in ITIL and the concept in BSM (Business Service Management) to analyze the “real” requirements from business units. II.Settle and implement the agreements: After clarify the relationship between business function and IT service, the most important document in SLM, SLA (Service Level Agreement), will be ready for recording the result of negotiation of two parties. It’s also good for addressing the responsibility. III.Review and improve the IT services: After implement, it’s necessary to review the result, and get the feedback for next service improvement. By continuous improvement, IT service will be able to match the business needs. In the case, we conduct the gap analysis between the expectation of business department and real performance of IT service. It helps IT department to understand “where we are” and “what we want”. Through the result of the comparison, it provides an obvious direction for service improvement, instead of by “intuition” only. It also includes other benefits like that: I.The IT department can realize its role in whole enterprise. It could have better cooperation with business department. II.The BSM helps IT manager to deploy its resources and optimize the investment in IT. III.The methodology provides a concrete, measurable standard and description to the business. It’s useful to establish the SLA and OLA (Operation Level Agreement). IV.The comparison between expectation and current status can show how the level of IT services support business services. V.The gap analysis provides the direction of service improvement. VI.The IT resources components are highlighted. Those components are major objects in backup mechanism and capacity management. VII.The Business/IT Knowledge base helps to review the range of monitor. VIII.The IT support system can be revealed. It is benefit to communication and problem management. The study shows that Service Level Management focus on how to restrict the action of IT Services provider. In other words, the whole process just helps to fine out the object of IT Services. It also needs support of other Service Support processes. Furthermore, the services’ quality improve will be showed by the Service Level Index. The SLM and other process complement to each other. To sum up, SLM is good for IT units to identifying needs and catching them. However, it should implement with other process to get better effect.