(LC)2^2: LiDAR-Camera Loop Constraints For Cross-Modal Place Recognition

Localization has been a challenging task for autonomous navigation. A loop detection algorithm must overcome environmental changes for the place recognition and re-localization of robots. Therefore, deep learning has been extensively studied for the consistent transformation of measurements into localization descriptors. Street view images are easily accessible; however, images are vulnerable to appearance changes. LiDAR can robustly provide precise structural information. However, constructing a point cloud database is expensive, and point clouds exist only in limited places. Different from previous works that train networks to produce shared embedding directly between the 2D image and 3D point cloud, we transform both data into 2.5D depth images for matching. In this work, we propose a novel cross-matching method, called (LC)$^2$, for achieving LiDAR localization without a prior point cloud map. To this end, LiDAR measurements are expressed in the form of range images before matching them to reduce the modality discrepancy. Subsequently, the network is trained to extract localization descriptors from disparity and range images. Next, the best matches are employed as a loop factor in a pose graph. Using public datasets that include multiple sessions in significantly different lighting conditions, we demonstrated that LiDAR-based navigation systems could be optimized from image databases and vice versa.Comment: 8 pages, 11 figures, Accepted to IEEE Robotics and Automation Letters (RA-L

CLARA: Classifying and Disambiguating User Commands for Reliable Interactive Robotic Agents

In this paper, we focus on inferring whether the given user command is clear, ambiguous, or infeasible in the context of interactive robotic agents utilizing large language models (LLMs). To tackle this problem, we first present an uncertainty estimation method for LLMs to classify whether the command is certain (i.e., clear) or not (i.e., ambiguous or infeasible). Once the command is classified as uncertain, we further distinguish it between ambiguous or infeasible commands leveraging LLMs with situational aware context in a zero-shot manner. For ambiguous commands, we disambiguate the command by interacting with users via question generation with LLMs. We believe that proper recognition of the given commands could lead to a decrease in malfunction and undesired actions of the robot, enhancing the reliability of interactive robot agents. We present a dataset for robotic situational awareness, consisting pair of high-level commands, scene descriptions, and labels of command type (i.e., clear, ambiguous, or infeasible). We validate the proposed method on the collected dataset, pick-and-place tabletop simulation. Finally, we demonstrate the proposed approach in real-world human-robot interaction experiments, i.e., handover scenarios

Acupuncture for Spasticity after Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The aim of this systematic review was to determine how effective acupuncture or electroacupuncture (acupuncture with electrical stimulation) is in treating poststroke patients with spasticity. We searched publications in Medline, EMBASE, and the Cochrane Library in English, 19 accredited journals in Korean, and the China Integrated Knowledge Resources Database in Chinese through to July 30, 2013. We included randomized controlled trials (RCTs) with no language restrictions that compared the effects of acupuncture or electroacupuncture with usual care or placebo acupuncture. The two investigators assessed the risk of bias and statistical analyses were performed. Three RCTs in English, 1 in Korean, and 1 in Chinese were included. Assessments were performed primarily with the Modified Ashworth Scale (MAS). Meta-analysis showed that acupuncture or electroacupuncture significantly decreased spasticity after stroke. A subgroup analysis showed that acupuncture significantly decreased wrist, knee, and elbow spasticity in poststroke patients. Heterogeneity could be explained by the differences in control, acupoints, and the duration after stroke occurrence. In conclusion, acupuncture could be effective in decreasing spasticity after stroke, but long-term studies are needed to determine the longevity of treatment effects

Traveltime and amplitude calculations using the damped wave solution

Because of its computational efficiency, prestack Kirchhoff depth migration remains the method of choice for all but the most complicated geological depth structures. Further improvement in computational speed and amplitude estimation will allow us to use such technology more routinely and generate better images. To this end, we developed a new, accurate, and economical algorithm to calculate first-arrival traveltimes and amplitudes for an arbitrarily complex earth model. Our method is based on numerical solutions of the wave equation obtained by using well-established finite-difference or finite-element modeling algorithms in the Laplace domain, where a damping term is naturally incorporated in the wave equation. We show that solving the strongly damped wave equation is equivalent to solving the eikonal and transport equations simultaneously at a fixed reference frequency, which properly accounts for caustics and other problems encountered in ray theory. Using our algorithm, we can easily calculate first-arrival traveltimes for given models. We present numerical examples for 2-D acoustic models having irregular topography and complex geological structure using a finite-element modeling code.This work was financially supported by National Research Laboratory Project of the Korea Ministry of Science and Technology, Brain Korea 21 project of the Korea Ministry of Education, grant No. R05-2000-00003 from the Basic Research Program of the Korea Science&Engineering Foundation, and grant No. PM10300 from Korea Ocean Research & Development Institute

Considering Commonsense in Solving QA: Reading Comprehension with Semantic Search and Continual Learning

Unlike previous dialogue-based question-answering (QA) datasets, DREAM, multiple-choice Dialogue-based REAding comprehension exaMination dataset, requires a deep understanding of dialogue. Many problems require multi-sentence reasoning, whereas some require commonsense reasoning. However, most pre-trained language models (PTLMs) do not consider commonsense. In addition, because the maximum number of tokens that a language model (LM) can deal with is limited, the entire dialogue history cannot be included. The resulting information loss has an adverse effect on performance. To address these problems, we propose a Dialogue-based QA model with Common-sense Reasoning (DQACR), a language model that exploits Semantic Search and continual learning. We used Semantic Search to complement information loss from truncated dialogue. In addition, we used Semantic Search and continual learning to improve the PTLM’s commonsense reasoning. Our model achieves an improvement of approximately 1.5% over the baseline method and can thus facilitate QA-related tasks. It contributes toward not only dialogue-based QA tasks but also another form of QA datasets for future tasks

Uptake of Soil-Residual Diazinon by Rotational Lettuce under Greenhouse Conditions

Pesticide residue is an increasing concern in rotational crop practices. The pesticide used for the primary crop may re-enter the secondary crop, thus exceeding pesticide levels set by the positive list system (PLS). As such, evaluation of pesticide residue translocated into rotational crops is required for ensuring pesticide safety. In this study, we investigated the residue pattern of diazinon translocated into lettuce as a typical rotational crop in Korea. Diazinon was used to treat greenhouse soil at the maximum annual application rate before crop planting. Diazinon residues in soil and lettuce were investigated using liquid chromatography/tandem mass spectroscopy and a modified quick, easy, cheap, effective, rugged, safe (QuEChERS) method. The limit of quantitation (LOQ) of diazinon was found as 0.005 mg/kg for the plant and soil samples. The recovery of diazinon at the LOQ and 10× the LOQ ranged from 100.2% to 108.7%. The matrix calibration curve showed linearity, with R2 values > 0.998. Diazinon residue in soil dissipated over time after the initial treatment, generating first-order kinetics (R2 = 0.9534) and having a half-life of about 22 days. The uptake ratio (UTR) of diazinon from the soil to the plant ranged from 0.002 to 0.026 over the harvest period. Considering the UTRs, diazinon residue in the edible leaf could exceed the PLS level (0.01 mg/kg) if lettuce is rotated in soil containing >0.357 mg/kg of diazinon. Based on our findings, to comply with the PLS, a 3-month plant-back interval is required following diazinon treatment and/or setting the maximum residue limit of diazinon for lettuce

Evolution of Depositional Environments in Response to the Holocene Sea-Level Change in the Lower Delta Plain of Nakdong River Delta, Korea

The Nakdong River delta, located in southeastern Korea, preserves thick and wide sediments, which are suitable for the high-resolution study of the evolution of depositional environments in the lower delta plain area. This study traces the Holocene evolution of the Nakdong River delta using deep drill core (ND-3; 46.60 m thick) sediments from the present delta plain. Sedimentary units of the sediments were classified based on grain size compositions and sedimentary structures: (A) alluvial zone, (B) estuarine zone, (C) shallow marine, (D) prodelta, (E) delta front, and (F) delta plain. The weathered sediment, paleosol, was observed at 43.16 m below the surface. There is an unconformity (43.10 m) to separate a Pleistocene sediment layer in the lowermost part differentiating from a Holocene sediment layer in the upper part of the core. The shallow marine sedimentary unit (32.20~23.50 m), in which grain size decreases upward is overlain by the prodelta unit (23.50~15.10 m), which consists of fine-grained sediments and relatively homogeneous sedimentary facies. The boundary between the delta front unit (15.10~8.00 m) and the delta plain unit (8.00~0.00 m) appears to lie at 8.0 m, and the variation in grain size is different; coarsening upward in the delta front unit and fining upward in the delta front unit, respectively. These sediments are characterized by a lot of sand–mud couplets and mica flakes aligned along with cross-stratification, which may be deposited in relatively high-energy environments. Until 13 cal ka BP, the sea level was 70 m below the present level and the drilling site might be located onshore. At 10 cal ka BP, the sea level was located 50 m below the present level and the drilling site might be moved to an estuarine environment. From 8 to 6 cal ka BP, a transgression phase occurred as a result of coastline invasion by the rapid rise of the sea level. Thus, the drilling site was drowned in a shallow marine environment. After 6 cal ka BP, the sea level reached the present level, and, since then, progradation might begin to form, primarily by more sediment input. After this period, the progradation phase continues as the sediments have advanced and the delta grows

Effectiveness and safety of electroacupuncture for poststroke patients with shoulder pain: study protocol for a double-center, randomized, patient- and assessor-blinded, sham-controlled, parallel, clinical trial

Abstract Background Practitioners of complementary and alternative medicine have suggested that acupuncture could alleviate poststroke shoulder pain, based on the clinical evidence. This study protocol is aimed at showing the effectiveness and safety of electroacupuncture therapy for stroke survivors with shoulder pain. Methods After assessing their eligibility, 60 stroke survivors with shoulder pain will be enrolled from two traditional Korean medicine hospitals and randomly divided into either the verum or the sham electroacupuncture (EA) group with a 1:1 ratio. The participants will receive 9 sessions of EA procedures for 3 weeks. The verum EA consists of needling on 6 unilateral acupoints (LI4, LI15, TE14, SI9, SI11, and GB21) with electronic stimulation. A non-penetrating Park sham device and fake electronic stimulation will be used in the sham group on the same acupoints. Patients and outcome assessors will be blinded throughout the entire study. A visual analog scale will be used primarily for the evaluation, and pain rating scale, Fugl-Meyer assessment for upper extremity, modified Ashworth scale, manual muscle test, passive range of motion test, Korean version of a modified Barthel index, and Korean version of the Beck depression inventory will be also be measured. A blinding index will be assessed. For safety, adverse events will be recorded. Data will be statistically analyzed by two-sample t-test or Wilcoxon rank sum test for efficacy and a chi-squared test or Fisher’s exact test for safety, at 5% of significance level. Discussion We expect this double-center, randomized, sham-controlled, patient- and assessor-blinded parallel trial to explore the effectiveness and safety of EA therapy, compared with sham EA, for poststroke shoulder pain. Trial registration https://clinicaltrials.gov/ct2/show/NCT0308686

Analysis of medical service utilization for post-stroke sequelae in Korea between 2016 and 2018: a cross-sectional study

Abstract In this retrospective cross-sectional observational study, the medical service utilization of post-stroke sequelae patients was examined using a national patient sample. The Korean Health Insurance Review and Assessment Service-National Patients Sample database was used to investigate the medical service utilization of 19,562 patients, diagnosed with post-stroke sequelae of cerebrovascular disease (I69) in Korea between January 2016 and December 2018. We compared the demographic characteristics, diagnosis code subtypes, frequency of healthcare utilization, medical costs, and comorbidities of standard care (SC) and Korean medicine (KM) users. Overall, patients aged ≥ 65 years accounted for the highest percentage, and utilization of medical services increased among patients aged ≥ 45 years. Outpatient care was higher among SC (79.23%) and KM (99.38%) users. Sequelae of cerebral infarction accounted for the highest percentage of diagnosis subtypes. Physical therapy and rehabilitation therapy were most frequent in SC, whereas injection/procedure and acupuncture were most frequent in KM. Cerebrovascular circulation/dementia drugs were prescribed most frequently in SC. Circulatory, digestive, endocrine, and metabolic disorders were the most common comorbidities in SC, whereas musculoskeletal and connective tissue disorders were most common in KM. Overall, SC and KM users showed differences in the number of medical service claims, cost of care, and comorbidities. Our findings provide basic research data for clinicians, researchers, and policy makers