Concordance invariants and the Turaev genus

We show that the differences between various concordance invariants of knots, including Rasmussen's $s$-invariant and its generalizations $s_n$-invariants, give lower bounds to the Turaev genus of knots. Using the fact that our bounds are nontrivial for some quasi-alternating knots, we show the additivity of Turaev genus for a certain class of knots. This leads us to the first example of an infinite family of quasi-alternating knots with Turaev genus exactly $g$ for any fixed positive integer $g$, solving a question of Champanerkar-Kofman.Comment: 6 pages, 3 figures. Some references are added or corrected. More descriptions on oriented band surgeries and slice-torus invariants are adde

Efficient Graduated Non-Convexity for Pose Graph Optimization

We propose a novel approach to Graduated Non-Convexity (GNC) and demonstrate its efficacy through its application in robust pose graph optimization, a key component in SLAM backends. Traditional GNC methods often rely on heuristic methods for GNC schedule, updating control parameter {\mu} for escalating the non-convexity. In contrast, our approach leverages the properties of convex functions and convex optimization to identify the boundary points beyond which convexity is no longer guaranteed, thereby eliminating redundant optimization steps in existing methodologies and enhancing both speed and robustness. We show that our method outperforms the state-of-the-art method in terms of speed and accuracy when used for robust back-end pose graph optimization via GNC. Our work builds upon and enhances the open-source riSAM framework. Our implementation can be accessed from: https://github.com/SNU-DLLAB/EGNC-PGOComment: 6 pages, 6 figure

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Fast Chip-Package-PCB Coanalysis Methodology for Power Integrity of Multi-domain High-Speed Memory: A Case Study

The power integrity of high-speed interfaces is an increasingly important issue in mobile memory systems. However, because of complicated design variations such as adjacent VDD domain coupling, conventional case-specific modeling is limited in analyzing trends in results from parametric variations. Moreover, conventional industrial methods can be simulated only after the design layout is completed and it requires a lot of back-annotation processes, which result in delayed delays time to market. In this paper, we propose a chip-package-PCB coanalysis methodology applied to our multi-domain high-speed memory system model with a current generation method. Our proposed parametric simulation model can analyze the tendency of power integrity results from variable sweeps and Monte Carlo simulations, and it shows a significantly reduced runtime compared to the conventional EDA methodology under JEDEC LPPDR4 environment.1

Skew control methodology for useful-skew implementation

Skew optimization is an important stage of the physical design. Previous studies suggested various skew optimization algorithms [1-7]. However, many of them have only focused on the zero-skew optimization [1-3], and several recent studies focus on a useful-skew optimization [5-7]. In this paper, we propose a novel skew optimization method for useful-skew implementation. Our proposed method generates optimal skew values, and applies them to a clock tree without any buffer insertion

GRASP based metaheuristics for layout pattern classification

Layout pattern classification has been recently utilized in IC design. It clusters hotspot patterns for design-space analysis or yield optimization. In pattern classification, an optimal clustering is essential, as well as its runtime and accuracy. Within the research-oriented infrastructure used in the ICCAD 2016 contest, we have developed a fast metaheuristic for the pattern classification that utilizes the Greedy Randomized Adaptive Search Procedure (GRASP). Our proposed metaheuristic outperforms the best-reported results on all of the ICCAD 2016 benchmarks. In addition, we achieve up to a 50% cluster count reduction, and improve a runtime significantly compared to a commercial EDA tool provided in the ICCAD 2016 contest [1]

Fast Predictive Useful Skew Methodology for Timing-Driven Placement Optimization

Incremental timing-driven placement (TDP) is one of the most crucial steps for timing closure in a physical design. The need for high-performance incremental TDP continues to grow, but prior studies have focused on optimizing only setup timing slacks, which can be easily stuck in local optima. In this paper, we present a useful skew methodology based on a maximum mean weight cycle (MMWC) approach in the incremental TDP. The proposed useful skew methodology finds an optimal clock latency for each flip-flop, and the clock latency is implemented by moving the flip-flops and/or reassigning them to local clock buffers. With the proposed TDP method, we effectively reduce the early slack of ICCAD 2015 contest benchmarks, and achieve 124(%) and 78(%) of total quality score improvement compared to the 2015 contest winner, and early slack histogram compression (EHC) method, respectively. Moreover, with fewer iterations in the optimization, the runtime of our predictive useful skew method is an average of 7.4 times faster than an EHC method