58 research outputs found

    Influence of mental model of GUI on usability

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    Applications operated on smartphones and other devices with a small user interface area on the screen and a large number of functions and contents will inevitably increase the number of operation procedures and make them more complicated. However, compared to the attention paid to information architecture and interaction in realizing intuitive user interfaces, less attention is paid to icons, and there are many examples where generic icons are used. Therefore, when icons and the functions they represent are different for each application, or when icons are unintelligible because of the distance between the user's mental model and the icons, the cognitive burden on the user is amplified, which may affect usability. We compared the usability of icons, one of the GUI elements, by focusing on their metaphors, and showed that the selection of metaphors that are in line with users' mental models has a positive effect on usability by improving the performance of task completion time and the number of errors. This study clarified the influence of the degree of congruence between the metaphor used and the user's mental model on the usability of icons, one of the GUI elements

    Neural Topological Ordering for Computation Graphs

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    Recent works on machine learning for combinatorial optimization have shown that learning based approaches can outperform heuristic methods in terms of speed and performance. In this paper, we consider the problem of finding an optimal topological order on a directed acyclic graph with focus on the memory minimization problem which arises in compilers. We propose an end-to-end machine learning based approach for topological ordering using an encoder-decoder framework. Our encoder is a novel attention based graph neural network architecture called \emph{Topoformer} which uses different topological transforms of a DAG for message passing. The node embeddings produced by the encoder are converted into node priorities which are used by the decoder to generate a probability distribution over topological orders. We train our model on a dataset of synthetically generated graphs called layered graphs. We show that our model outperforms, or is on-par, with several topological ordering baselines while being significantly faster on synthetic graphs with up to 2k nodes. We also train and test our model on a set of real-world computation graphs, showing performance improvements.Comment: To appear in NeurIPS 202

    Nine-Year Survival of Lymphoblastic Lymphoma Patients

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    This study aimed to analyze the overall survival period of adult lymphoblastic lymphoma patients treated with various therapeutic regimens, and to assess the determinants affecting survival outcome. Twenty-five adult patients with lymphoblastic lymphoma who had been treated at Severance Hospital, Yonsei University College of Medicine, Seoul, Korea from June 1996 to June 2005 were analyzed retrospectively. As an initial remission induction chemotherapy, the hyper-CVAD regimen was performed in eight patients, the Stanford/Northern California Oncology Group (NCOG) regimen in five, the CAVOP regimen in four, the m-BACOP regimen in three, and the CHOP regimen in one patient. Patients were divided into two groups according to their therapeutic modalities. Twenty patients received conventional chemotherapy alone and five received subsequent PBSCT after conventional chemotherapy. Four patients of the PBSCT group underwent autologous PBSCT and one underwent allogeneic PBSCT. The overall response rate was 80% (60% showing a complete response, 20% showing a partial response) and the relapse rate was 73.3%. The overall survival (OS) rate was 55.1% at 1 year, 31.5% at 5 years, and 23.6% at 9 years. The disease-free survival (DFS) rate was 46.7% at 1 year and 30.0% at 7 years. The 5-year OS rate in relation to the regimens was 60% with the Stanford/NCOG regimen, 50% with the CAVOP regimen, and 33.3% with the m-BACOP regimen. The patients treated with the hyper-CVAD regimen had an 18.2% 2-year OS rate, and other patients with CHOP or COPBLAM-V expired early in their course. The OS rate in patients treated with conventional chemotherapy alone was 19.8%, whereas patients treated with subsequent PBSCT after chemotherapy showed 50% overall survival (p = 0.25). The age at presentation influenced the outcome of the patients (p = 0.01). The Stanford/NCOG regimen is an effective initial choice of therapy for lymphoblastic lymphoma patients, and is superior to the hyper-CVAD regimen in complete response rate and overall survival rate (p = 0.36). Addition of PBSCT after chemotherapy may be needed for achieving optimal outcomes

    Psychiatric Comorbidity in Korean Children and Adolescents with Attention-Deficit Hyperactivity Disorder: Psychopathology According to Subtype

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    It is well-known that more than 50% of attention-deficit hyperactivity disorder (ADHD) cases also have comorbid psychiatric disorders. We evaluated the comorbid psychopathology of Korean children and adolescents with ADHD using a standardized diagnostic instrument. The Korean Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (K-SADS-PL-K) was administered and completed in 105 patients who had been referred to the outpatient and inpatient clinics at the Samsung Medical Center from March 2004 to May 2005. All of the cases were diagnosed as ADHD according to DSM-IV criteria. We analyzed their clinical characteristics and psychiatric comorbidities, and assessed the correlation of any comorbidity with gender, age and ADHD subtype. Among our 105 participants, 70 (66.7%) subjects were diagnosed with combined-type ADHD, 22 (21.0%) were the predominantly inattentive type, only 1 (1.0%) was determined to have the predominantly hyperactive-impulsive type of ADHD, and 12 (11.4%) were classified as not otherwise specified (NOS) ADHD. Eighty (76.2%) subjects had at least one comorbid disorder such as oppositional defiant disorder (n = 53, 50.5%), anxiety disorders (n = 35, 33.3%) and affective disorders (n = 15, 14.3%). Our patients ranged in age from five to 16 years. Among the factors including gender, age, and ADHD subtype, ADHD subtype was the only one significant to comorbidity in our study. The results of this study suggest that psychiatric comorbidity in Korean children with ADHD is similar to the results of previous studies in western countries. Out of all the ADHD subtypes, the combined-type group had a significantly higher ratio of comorbid disorders and psychopathologies

    Prediction of Flow Velocity from the Flexural Vibration of a Fluid-Conveying Pipe Using the Transfer Function Method

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    This study presents a method to predict the flow velocity in a fluid-conveying pipe using vibration signals from the pipe surface. The flexural vibration of a fluid pipe is investigated through wave propagation. The wavenumbers and mode shapes of the pipe are determined based on its mechanical properties and flow velocities. The transient components of wavenumbers at low frequencies vary and converge on all values at higher frequencies as the flow velocity is increased. While the stationary fluid pipe exhibits symmetrical mode shapes, pipes with increasing flow velocities exhibit an asymmetric mode shape distribution skewed on one side of the axis. The resonant frequencies shift to the low frequency side as the flow velocity increases. The analytical results of the vibration analysis are used in the transfer function method to predict the flow velocities. To validate the accuracy of the prediction method, numerical vibration signals simulated by the finite element model are used. The actual input flow velocity is compared with the numerical results regarding the same to gauge the accuracy of the prediction method. This method can be used to monitor the flow rate without using flow meters, and thus protect pipelines from sudden malfunction

    Flexural Vibration Analysis of Nuclear Fuel Rod Bundles Interacting with Surrounding Fluid Subjected to Pressure Wave

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    The structural behavior of the nuclear rod bundles that consisted of cylindrical beams was predicted using the spectral element method (SEM) while considering the interaction with the surrounding fluid. Viscous fluid behavior was utilized in order to calculate the forces acting on the nuclear rod bundles from the incident pressure waves. The added mass and fluid coupling on the nuclear rod bundles were determined for the position patterns and gaps of each of the cylindrical beams. The pressure field from propagating waves in the surrounding fluid was calculated with respect to the boundary conditions of the surface of the vibrating structures. With the increasing number of nuclear rods and decreasing pressure wavelengths, the structural vibration of the nuclear rod bundles that were induced by the propagating forces affected the scattering events of the pressure field. The frequency response of the nuclear rod bundles from the pressure waves in the water exhibited smaller damping, because the incident pressure wave travels without fluid coupling due to the longer wavelength when compared with distance between rods. The proposed numerical method can be utilized for the detailed design for effective parameters of a supporting system to reduce the vibration of nuclear fuel rod bundles for safety control

    High resolution size characterization of particulate contaminants for radioactive metal waste treatment

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    To regulate the safety protocols in nuclear facilities, radioactive aerosols have been extensively researched to understand their health impacts. However, most measured particle-size distributions remain at low resolutions, with the particle sizes ranging from nanometer to micrometer. This study combines the high-resolution detection of 500 size classes, ranging from 6 nm to 10 μm, for aerodynamic diameter distributions, with a regional lung deposition calculation. We applied the new approach to characterize particle-size distributions of aerosols generated during the plasma arc cutting of simulated non-radioactive steel alloy wastes. The high-resolution measured data were used to calculate the deposition ratios of the aerosols in different lung regions. The deposition ratios in the alveolar sacs contained the dominant particle sizes ranging from 0.01 to 0.1 μm. We determined the distribution of various metals using different vapor pressures of the alloying components and analyzed the uncertainties of lung deposition calculations using the low-resolution aerodynamic diameter data simultaneously. In high-resolution data, the changes in aerosols that can penetrate the blood system were better captured, correcting their potential risks by a maximum of 42%. The combined calculations can aid the enhancement of high-resolution measuring equipment to effectively manage radiation safety in nuclear facilities

    Exposure and Risk Assessment of Second- and Third-Hand Tobacco Smoke Using Urinary Cotinine Levels in South Korea

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    Exposure to environmental tobacco smoke (ETS) is the reason for approximately 1% of global mortality. ETS exposure can happen either as inhalation of direct cigarette smoke (second-hand smoke) or its associated residue particles (third-hand smoke), especially when living with a smoker in the same family. This study investigated the association between the urinary cotinine levels, as biomarkers of exposure to tobacco smoke, of smokers and those exposed to second-hand and third-hand smoke while living in the same family, through a Korean nationwide survey. Direct assessment of ETS exposure and its lifetime effect on human health is practically difficult. Therefore, this study evaluated the internal estimated daily intake (I-EDI) of nicotine and equivalent smoked cigarette per day (CPD). The carcinogenic and non-carcinogenic inhalation risks of ETS exposure were assessed by considering the calculated equivalent CPD and composition of cigarette smoke of high-selling cigarette brands in South Korea. The results show that there is a statistically significant positive correlation between the cotinine levels of smokers and those of the non-smokers living in the same family. The risk assessment results yielded that hazard index (HI) and total excess lifetime cancer risk (ECR) for both second-hand and third-hand smoke exposure can exceed 1 and 1 × 10−6, respectively, especially in women and children. In the composition of the cigarette smoke, 1,3-butadiene and acrolein substances had the highest contribution to HI and ECR. Consequently, the provision of appropriate plans for smoking cessation as a strategy for the prevention of ETS exposure to women and children is deemed necessary
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