Transformations of High-Level Synthesis Codes for High-Performance Computing

Specialized hardware architectures promise a major step in performance and energy efficiency over the traditional load/store devices currently employed in large scale computing systems. The adoption of high-level synthesis (HLS) from languages such as C/C++ and OpenCL has greatly increased programmer productivity when designing for such platforms. While this has enabled a wider audience to target specialized hardware, the optimization principles known from traditional software design are no longer sufficient to implement high-performance codes. Fast and efficient codes for reconfigurable platforms are thus still challenging to design. To alleviate this, we present a set of optimizing transformations for HLS, targeting scalable and efficient architectures for high-performance computing (HPC) applications. Our work provides a toolbox for developers, where we systematically identify classes of transformations, the characteristics of their effect on the HLS code and the resulting hardware (e.g., increases data reuse or resource consumption), and the objectives that each transformation can target (e.g., resolve interface contention, or increase parallelism). We show how these can be used to efficiently exploit pipelining, on-chip distributed fast memory, and on-chip streaming dataflow, allowing for massively parallel architectures. To quantify the effect of our transformations, we use them to optimize a set of throughput-oriented FPGA kernels, demonstrating that our enhancements are sufficient to scale up parallelism within the hardware constraints. With the transformations covered, we hope to establish a common framework for performance engineers, compiler developers, and hardware developers, to tap into the performance potential offered by specialized hardware architectures using HLS

A Simple Dynamic Spanner via APSP

We give a simple algorithm for maintaining a n^{o(1)}-approximate spanner H of a graph G with n vertices as G receives edge updates by reduction to the dynamic All-Pairs Shortest Paths (APSP) problem. Given an initially empty graph G, our algorithm processes m insertions and n deletions in total time m^{1 + o(1)} and maintains an initially empty spanner H with total recourse n^{1 + o(1)}. When the number of insertions is much larger than the number of deletions, this notably yields recourse sub-linear in the total number of updates. Our simple algorithm can be extended to maintain a δ ≥ ω(1)-approximate spanner with n^{1+o(1)} edges throughout a sequence of m insertions and D deletions with amortized update time n^{o(1)} and total recourse n^{1 + o(1)} + n^{o(1)} ⋅ D via batching

A Dynamic Shortest Paths Toolbox: Low-Congestion Vertex Sparsifiers and their Applications

We present a general toolbox, based on new vertex sparsifiers, for designing data structures to maintain shortest paths in dynamic graphs. In an $m$-edge graph undergoing edge insertions and deletions, our data structures give the first algorithms for maintaining (a) $m^{o(1)}$-approximate all-pairs shortest paths (APSP) with \emph{worst-case} update time $m^{o(1)}$ and query time $\tilde{O}(1)$, and (b) a tree $T$ that has diameter no larger than a subpolynomial factor times the diameter of the underlying graph, where each update is handled in amortized subpolynomial time. In graphs undergoing only edge deletions, we develop a simpler and more efficient data structure to maintain a $(1+\epsilon)$-approximate single-source shortest paths (SSSP) tree $T$ in a graph undergoing edge deletions in amortized time $m^{o(1)}$ per update. Our data structures are deterministic. The trees we can maintain are not subgraphs of $G$, but embed with small edge congestion into $G$. This is in stark contrast to previous approaches and is useful for algorithms that internally use trees to route flow. To illustrate the power of our new toolbox, we show that our SSSP data structure gives simple deterministic implementations of flow-routing MWU methods in several contexts, where previously only randomized methods had been known. To obtain our toolbox, we give the first algorithm that, given a graph $G$ undergoing edge insertions and deletions and a dynamic terminal set $A$, maintains a vertex sparsifier $H$ that approximately preserves distances between terminals in $A$, consists of at most $|A|m^{o(1)}$ vertices and edges, and can be updated in worst-case time $m^{o(1)}$. Crucially, our vertex sparsifier construction allows us to maintain a low edge-congestion embedding of $H$ into $G$, which is needed for our applications

Koreanische Unternehmen in Deutschland: Entwicklung und Standortfragen

Fünf Jahre nach der Asienkrise von 1997/98 erscheint offenkundig, dass der Aufstieg der Region zu einer der drei zentralen Säulen der Weltwirtschaft nur kurzfristig abgebremst wurde. Gerade ein Land wie die Republik Korea (im Folgenden: Korea) hat die Chancen eines schmerzhaften, aber in vielen Bereichen höchst effektiven Reformprozesses genutzt, um sich noch besser in der Weltwirtschaft zu positionieren. Daran ändern auch die konjunkturellen Probleme im Jahre 2003 nichts Grundlegendes, die zum Teil auf eine gewisse Überhitzung zurückzuführen sind

Hand in Hand: Sozialpädagogik und Jugendstrafvollzug: Wie die Sozialpädagogik jugendlichen Straftäter*innen auf ihrem Weg im Strafvollzug begleitet

Die vorliegende Bachelorarbeit von Sarah Meierhans befasst sich mit sozialpädagogischen Interventionen bei delinquenten Jugendlichen. Vor dem Hintergrund der Jugendkriminalität und der Notwendigkeit erzieherischer Interventionen kommt der Sozialpädagogik eine zentrale Rolle zu. Ziel dieser Arbeit ist es aufzuzeigen, welche Rolle die Sozialpädagogik im Jugendstrafvollzug spielt und wie erzieherische Massnahmen dazu beitragen, die spätere Wiedereingliederung jugendlicher Straftäter in die Gesellschaft zu erleichtern. Die theoretischen Grundlagen der Sozialpädagogik im Kontext straffälliger Jugendlicher werden unter Einbeziehung der erzieherischen Prinzipien des Jugendstrafrechts dargestellt. Verschiedene Ansätze und Methoden der Sozialpädagogik im Kontext straffälliger Jugendlicher werden vorgestellt, darunter Empowerment, berufliche Integration und Beziehungsgestaltung. Zusammenfassend unterstreicht die Bachelorarbeit die entscheidende Rolle der Sozialpädagogik bei der Unterstützung von jugendlichen Straftätern. Durch die gezielte Förderung von sozialen Fähigkeiten und der individuellen Ressourcen werden die Chancen auf ein straffreies Leben erhöht.+ Code Diss LU: hslusa basp + Fussnote: Bachelor-Arbeit, Hochschule Luzern – Soziale Arbeit, Studienrichtung Sozialpädagogik, 2023 + NL-Code: NLLUHSA20230

Koreanische Unternehmen in Deutschland: Entwicklung und Standortfragen

Fünf Jahre nach der Asienkrise von 1997/98 erscheint offenkundig, dass der Aufstieg der Region zu einer der drei zentralen Säulen der Weltwirtschaft nur kurzfristig abgebremst wurde. Gerade ein Land wie die Republik Korea hat die Chancen eines schmerzhaften, aber in vielen Bereichen höchst effektiven Reformprozesses genutzt, um sich noch besser in der Weltwirtschaft zu positionieren. Daran ändern auch die konjunkturellen Probleme im Jahre 2003 nichts Grundlegendes, die zum Teil auf eine gewisse Überhitzung zurückzuführen sind

Pre-operative gastric ultrasound in patients at risk of pulmonary aspiration: a prospective observational cohort study.

Point-of-care gastric sonography offers an objective approach to assessing individual pulmonary aspiration risk before induction of general anaesthesia. We aimed to evaluate the potential impact of routine pre-operative gastric ultrasound on peri-operative management in a cohort of adult patients undergoing elective or emergency surgery at a single centre. According to pre-operative gastric ultrasound results, patients were classified as low risk (empty, gastric fluid volume ≤ 1.5 ml.kg-1 body weight) or high risk (solid, mixed or gastric fluid volume > 1.5 ml.kg-1 body weight) of aspiration. After sonography, examiners were asked to indicate changes in aspiration risk management (none; more conservative; more liberal) to their pre-defined anaesthetic plan and to adapt it if patient safety was at risk. We included 2003 patients, 1246 (62%) of which underwent elective and 757 (38%) emergency surgery. Among patients who underwent elective surgery, 1046/1246 (84%) had a low-risk and 178/1246 (14%) a high-risk stomach, with this being 587/757 (78%) vs. 158/757 (21%) among patients undergoing emergency surgery, respectively. Routine pre-operative gastric sonography enabled changes in anaesthetic management in 379/2003 (19%) of patients, with these being a more liberal approach in 303/2003 (15%). In patients undergoing elective surgery, pre-operative gastric sonography would have allowed a more liberal approach in 170/1246 (14%) and made a more conservative approach indicated in 52/1246 (4%), whereas in patients undergoing emergency surgery, 133/757 (18%) would have been managed more liberally and 24/757 (3%) more conservatively. We showed that pre-operative gastric ultrasound helps to identify high- and low-risk situations in patients at risk of aspiration and adds useful information to peri-operative management. Our data suggest that routine use of pre-operative gastric ultrasound may improve individualised care and potentially impact patient safety

Almost-Linear Time Algorithms for Incremental Graphs: Cycle Detection, SCCs, ss-tt Shortest Path, and Minimum-Cost Flow

We give the first almost-linear time algorithms for several problems in incremental graphs including cycle detection, strongly connected component maintenance, $s$-$t$ shortest path, maximum flow, and minimum-cost flow. To solve these problems, we give a deterministic data structure that returns a $m^{o(1)}$-approximate minimum-ratio cycle in fully dynamic graphs in amortized $m^{o(1)}$ time per update. Combining this with the interior point method framework of Brand-Liu-Sidford (STOC 2023) gives the first almost-linear time algorithm for deciding the first update in an incremental graph after which the cost of the minimum-cost flow attains value at most some given threshold $F$. By rather direct reductions to minimum-cost flow, we are then able to solve the problems in incremental graphs mentioned above. At a high level, our algorithm dynamizes the $\ell_1$ oblivious routing of Rozho\v{n}-Grunau-Haeupler-Zuzic-Li (STOC 2022), and develops a method to extract an approximate minimum ratio cycle from the structure of the oblivious routing. To maintain the oblivious routing, we use tools from concurrent work of Kyng-Meierhans-Probst Gutenberg which designed vertex sparsifiers for shortest paths, in order to maintain a sparse neighborhood cover in fully dynamic graphs. To find a cycle, we first show that an approximate minimum ratio cycle can be represented as a fundamental cycle on a small set of trees resulting from the oblivious routing. Then, we find a cycle whose quality is comparable to the best tree cycle. This final cycle query step involves vertex and edge sparsification procedures reminiscent of previous works, but crucially requires a more powerful dynamic spanner which can handle far more edge insertions. We build such a spanner via a construction that hearkens back to the classic greedy spanner algorithm

Gastric Ultrasound Performance Time and Difficulty : A Prospective Observational Study

Introduction Point‐of‐care gastric ultrasound is an emerging tool in peri‐operative practice. However, data on the technical challenges of gastric ultrasound, which are essential for optimised training, remain scarce. We analysed gastric ultrasound examinations performed after basic training to identify factors associated with difficulty. Methods This was an analysis of data from a prospective observational study evaluating the potential impact of routine pre‐operative gastric ultrasound on peri‐operative management in adult patients undergoing elective or emergency surgery at a single centre. Before initiation, physicians received extensive structured training with at least 30 supervised gastric sonograms before independent practice. We then used regression models to identify factors associated with deviation from a predefined sonography algorithm, performance time and scan difficulty. Results Seventy‐three trained physicians performed 2003 ultrasound scans. Median (IQR [range]) performance time was 5 (4–6 [1–20]) min, which was achieved after 20–27 scans following structured training. Patient characteristics associated with more difficult and longer duration scans were: increase in BMI per 5 kg.m$^{‐2}$ (odds ratio (95%CI) 1.57 (1.35–1.83), p < 0.001 for difficulty and percentage change coefficient (95%CI) 1.03 (1.02–1.05), p < 0.001 for duration); and male sex (odds ratio (95%CI) 3.31 (2.28–4.88), p < 0.001 for difficulty and percentage change coefficient (95%CI) 1.08 (1.04–1.12), p < 0.001, for duration). Trauma surgery (odds ratio (95%CI) 3.26 (1.88–5.68), p < 0.001), ASA physical status of 3 or 4 (odds ratio (95%CI) 1.86 (1.21–2.88), p = 0.0049) and emergency surgery (odds ratio (95%CI) 1.86 (1.20–2.89), p = 0.006) were associated with deviation from the predefined sonography algorithm. Discussion Approximately 50 scans are required to achieve a baseline performance of 5 min per gastric ultrasound. Future training programmes should focus on patients with obesity, male sex, higher ASA physical status and trauma