Curriculum Learning and Imitation Learning for Model-free Control on Financial Time-series

Curriculum learning and imitation learning have been leveraged extensively in the robotics domain. However, minimal research has been done on leveraging these ideas on control tasks over highly stochastic time-series data. Here, we theoretically and empirically explore these approaches in a representative control task over complex time-series data. We implement the fundamental ideas of curriculum learning via data augmentation, while imitation learning is implemented via policy distillation from an oracle. Our findings reveal that curriculum learning should be considered a novel direction in improving control-task performance over complex time-series. Our ample random-seed out-sample empirics and ablation studies are highly encouraging for curriculum learning for time-series control. These findings are especially encouraging as we tune all overlapping hyperparameters on the baseline -- giving an advantage to the baseline. On the other hand, we find that imitation learning should be used with caution.Comment: AAAI 2024 AI4TS Workshop Ora

Perseus: Removing Energy Bloat from Large Model Training

Training large AI models on numerous GPUs consumes a massive amount of energy. We observe that not all energy consumed during training directly contributes to end-to-end training throughput, and a significant portion can be removed without slowing down training, which we call energy bloat. In this work, we identify two independent sources of energy bloat in large model training, intrinsic and extrinsic, and propose Perseus, a unified optimization framework that mitigates both. Perseus obtains the "iteration time-energy" Pareto frontier of any large model training job using an efficient iterative graph cut-based algorithm and schedules energy consumption of its forward and backward computations across time to remove intrinsic and extrinsic energy bloat. Evaluation on large models like GPT-3 and Bloom shows that Perseus reduces energy consumption of large model training by up to 30%, enabling savings otherwise unobtainable before.Comment: Open-source at https://ml.energy/zeus/perseus

iCSDB: an integrated database of CRISPR screens.

High-throughput screening based on CRISPR-Cas9 libraries has become an attractive and powerful technique to identify target genes for functional studies. However, accessibility of public data is limited due to the lack of user-friendly utilities and up-to-date resources covering experiments from third parties. Here, we describe iCSDB, an integrated database of CRISPR screening experiments using human cell lines. We compiled two major sources of CRISPR-Cas9 screening: the DepMap portal and BioGRID ORCS. DepMap portal itself is an integrated database that includes three large-scale projects of CRISPR screening. We additionally aggregated CRISPR screens from BioGRID ORCS that is a collection of screening results from PubMed articles. Currently, iCSDB contains 1375 genome-wide screens across 976 human cell lines, covering 28 tissues and 70 cancer types. Importantly, the batch effects from different CRISPR libraries were removed and the screening scores were converted into a single metric to estimate the knockout efficiency. Clinical and molecular information were also integrated to help users to select cell lines of interest readily. Furthermore, we have implemented various interactive tools and viewers to facilitate users to choose, examine and compare the screen results both at the gene and guide RNA levels. iCSDB is available at https://www.kobic.re.kr/icsdb/

A database of 5305 healthy Korean individuals reveals genetic and clinical implications for an East Asian population

Despite substantial advances in disease genetics, studies to date have largely focused on individuals of European descent. This limits further discoveries of novel functional genetic variants in other ethnic groups. To alleviate the paucity of East Asian population genome resources, we established the Korean Variant Archive 2 (KOVA 2), which is composed of 1896 whole-genome sequences and 3409 whole-exome sequences from healthy individuals of Korean ethnicity. This is the largest genome database from the ethnic Korean population to date, surpassing the 1909 Korean individuals deposited in gnomAD. The variants in KOVA 2 displayed all the known genetic features of those from previous genome databases, and we compiled data from Korean-specific runs of homozygosity, positively selected intervals, and structural variants. In doing so, we found loci, such as the loci of ADH1A/1B and UHRF1BP1, that are strongly selected in the Korean population relative to other East Asian populations. Our analysis of allele ages revealed a correlation between variant functionality and evolutionary age. The data can be browsed and downloaded from a public website (https://www.kobic.re.kr/kova/). We anticipate that KOVA 2 will serve as a valuable resource for genetic studies involving East Asian populations

CaPSSA: visual evaluation of cancer biomarker genes for patient stratification and survival analysis using mutation and expression data

Predictive biomarkers for patient stratification play critical roles in realizing the paradigm of precision medicine. Molecular characteristics such as somatic mutations and expression signatures represent the primary source of putative biomarker genes for patient stratification. However, evaluation of such candidate biomarkers is still cumbersome and requires multistep procedures especially when using massive public omics data. Here, we present an interactive web application that divides patients from large cohorts (e.g. The Cancer Genome Atlas, TCGA) dynamically into two groups according to the mutation, copy number variation or gene expression of query genes. It further supports users to examine the prognostic value of resulting patient groups based on survival analysis and their association with the clinical features as well as the previously annotated molecular subtypes, facilitated with a rich and interactive visualization. Importantly, we also support custom omics data with clinical information.N

Performance Prediction and Validation of a Small-Capacity Twisted Savonius Wind Turbine

In this study, an off-grid−type small wind turbine for street lighting was designed and analyzed. Its performance was predicted using a computational fluid dynamics model. The proposed wind turbine has two blades with a radius of 0.29 m and a height of 1.30 m. Ansys Fluent, a commercial computational fluid dynamics solver, was used to predict the performance, and the k-omega SST model was used as the turbulence model. The simulation result revealed a tip-speed ratio of 0.54 with a maximum power coefficient, or an aerodynamic rotor efficiency of 0.17. A wind turbine was installed at a measurement site to validate the simulation, and a performance test was used to measure the power production. To compare the simulation results obtained from the CFD simulation with the measured electrical power performance, the efficiencies of the generator and the controller were measured using a motor-generator testbed. Also, the control strategy of the controller was found from the field test and applied to the simulation results. Comparing the results of the numerical simulation with the experiment, the maximum power-production error at the same wind speed was found to be 4.32%

Evaluation of Pre-Transfusion Crossmatch Test Using Microscanner C3

A pre-transfusion crossmatch test is crucial for ensuring safe blood transfusions by identifying the compatibility between donor and recipient blood samples. Conventional tube methods for crossmatching have limitations, including subjectivity in result interpretation and the potential for human error. In this study, we evaluated the diagnostic performance of a new crossmatch test using Microscanner C3, which can overcome these shortcomings. The crossmatch test results using the method were obtained in 323 clinical samples. The sensitivity, specificity, positive predictive value, negative predictive value, and concordance rate of the crossmatch test using Microscanner C3 were 98.20%, 100.00%, 100.00%, 98.11%, and 99.07%, respectively. The diagnostic performance of the new system offers a promising alternative to conventional tube methods for pre-transfusion crossmatch testing. Microscanner C3 could also increase the automation, standardization, and accuracy of crossmatch tests. The crossmatch test using Microscanner C3 is thought to increase the efficiency and reliability in identifying blood samples suitable for transfusion, thereby improving patient safety and optimizing the use of blood products in clinical settings

Recent trends in renewable energy resources for power generation in the Republic of Korea

The global demand for renewable energy in recent decades has continued to increase, despite adverse economic conditions such as world economic recessions, trade disputes, and falls in gas and oil prices. During this period, the United States and Europe have led the development of renewable energy technologies, but now emerging countries such as China, Brazil, India, and the Republic of Korea are also been actively participating in developing and deploying renewable energy. For example, since 1989, the Korea Electric Power Corporation has built a well-known test site for the application of renewable energy resources, including 500 kW photovoltaic systems with smooth integration into power grids in the Gochang area. The main objects of this study are (1) to review the recent trends in renewable energy systems, including solar, wind, bioenergy, hydroelectric, and tidal power, for electric power generation developed in Korea and (2) to introduce the test sites in Korea. For this purpose, this study examines the current activities of industry and government in Korea and compares them with global trends

Effect of ionotropic gelation of COOH-functionalized polymeric binders in multivalent ion batteries

Multivalent ion batteries (MIBs) have received much attention as alternatives to the current lithium-ion batteries (LIBs) because of their high energy density and the possibility of using raw materials with high natural abundance. However, the mechanochemical stability and key electrochemical performance of MIB electrodes are easily impaired during cycling by the large volume expansion of active materials and sluggish ion transport, raising the necessity of developing advanced binder designs. Herein, we report a systematic investigation of polysaccharide and polyacrylic acid binders with carboxylic acid functional groups for MIBs based on Mg2+, Ca2+, Zn2+, and Al3+ in comparison with their monovalent counterpart. These binders with carboxylic acid functional groups form a rigid passivation layer on the electrode surface via the so-called egg-box mechanism involving the multivalent cations, imposing resistance and shortening the cycle life of the MIB cells. The series of comparative analyses provide useful information on the effect and design of popular carboxylic acid-functionalized binders for incorporation in MIBs.N