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91.
Pulmonary alveolar microlithiasis was found in three siblings. Only the youngest of them, a former smoker, developed endstage lung disease. The other two are asymptomatic with normal lung function despite impressive changes on all chest radiographs. The role of smoking in perpetuating microlithiasis and furthering the progression of this disease is discussed. 相似文献
92.
P. Chauviere K. H. Jung D. K. Kim H. C. Lee S. H. Kang Y. T. Im 《Journal of Mechanical Science and Technology》2008,22(5):924-930
A tip test was developed and used successfully for friction measurement between the billet and dies or punches for the cold
forging process. In the present investigation, the test was downsized and experimentally investigated to find the size effect
on test results. For the test, aluminum alloys of 2024-O and 6061-O were used and the specimen was made into a cylinder of
diameter and height of 10.0mm and 5.0mm, respectively. For lubrications, VG32, VG100, grease, and corn oil were used in experiments
and tests were also carried out with two different humidity conditions. A micro-hardness test was made to compare the hardness
distribution with the strain distribution obtained from the finite element simulation. The load levels and tip distances were
measured for Al6061-O specimen with various lubrication conditions and compared to each other to find any correlation between
the two. The shear friction factors were determined for various lubrications by using the finite element simulation under
the present condition. 相似文献
93.
In this paper, we computationally investigate the fundamental aspects of autoignition and subsequent combustion phenomena in low temperature combustion (LTC) engine environments using direct numerical simulations (DNS). In particular, the effects of thermal and equivalence ratio stratification on the autoignition and subsequent front propagation in high pressure and stratified hydrogen-air turbulent mixtures are studied using detailed chemistry. Depending on fuel injection timing, exhaust gas recirculation, and wall heat loss, different correlations between temperature (T) – equivalence ratio (?) fields can exist prior to the major heat release event. Here, we investigate three cases with different initial T–? correlations: (A) a baseline case of a uniform composition with temperature inhomogeneities only, (B) uncorrelated T–? fields, and (C) negatively-correlated T–? fields. Numerical diagnostics are developed based on an appropriately defined Damköhler number to distinguish different modes of heat release. It is found that the majority of heat release in the baseline case and the uncorrelated case occurs during the front propagation in the form of both spontaneous ignition fronts as well as deflagration waves, whereas the negatively correlated case ignites predominantly homogeneously. 相似文献
94.
Qianqian Liu Yu-Jin Kim Gwang-Bum Im Jintao Zhu Yuzhou Wu Yijing Liu Suk Ho Bhang 《Advanced functional materials》2021,31(12):2008171
Inorganic nanoparticles (NPs) offer significant advantages to the biomedical field owing to their large surface area, controllable structures, diverse surface chemistry, and unique optical and physical properties. Researchers worldwide have shown that inorganic NPs and the released metal ions can act as therapeutic agents in targeted tissues or to cure various diseases without acute toxicity. In this progress report, the recent developments in inorganic NPs with different compositions directly used as therapeutics are discussed. First, the recent convergence of nanotechnology and biotechnology in biomedical applications as well as the unique functions, features, and advantages of inorganic NPs in biomedical applications are summarized. Thereafter, the biological effects of inorganic compositions in NPs which include balancing the intracellular redox environment, regulating the specific cellular signaling and cellular behaviors, and apoptosis are explained. In addition, the emerging therapeutic applications of inorganic NPs in various diseases are exemplified. Finally, the perspectives and challenges for overcoming the weaknesses of inorganic NPs as therapeutics are discussed. By carefully considering and investigating the biological effects of inorganic NPs and metal ions released from NPs, more promising inorganic NPs based therapeutic agents can be developed. 相似文献
95.
Kim Jung-Yeon Lee Suhwan Lee Hee Bum Kang Byeong-Gwon Im Soo-Bin Nam Yunyoung 《The Journal of supercomputing》2021,77(8):8374-8390
The Journal of Supercomputing - The purpose of this study is to investigate gait in patients with neurological disorders using accelerometers. Accelerometers were placed on both ankles of... 相似文献
96.
Nguyen Sy-Ngoc Truong-Quoc Chien Han Jang-woo Im Sunyoung Cho Maenghyo 《Journal of Mechanical Science and Technology》2021,35(10):4643-4654
Journal of Mechanical Science and Technology - Recurrent neural network (RNN)-based accelerated prediction was achieved for the long-term time-dependent behavior of viscoelastic composite laminated... 相似文献
97.
Wonjun Choi Sungjae Hong Yeonsu Jeong Yongjae Cho Hyung Gon Shin Ji Hoon Park Yeonjin Yi Seongil Im 《Advanced functional materials》2021,31(9):2009436
Among many of 2D semiconductor-based devices, type III PN junction diodes are given special attentions due to their unique function, negative differential resistance (NDR). However, it has been found uneasy to achieve well-matched type III PN junctions from 2D–2D van der Waals heterojunctions. Here, the authors present other alternatives of type III heterojunctions, using 2D p-MoTe2/organic n-type dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) and 2D p-WSe2/n-MoOx systems. Those junction diodes appear to well-demonstrate static and dynamic NDR behavior via resonant tunneling and electron–hole recombination. Extended to an inverter circuit, p-MoTe2/n-HAT-CN diode enables multilevel inverter characteristics as monolithically integrated with p-MoTe2 channel field effect transistor. The same NDR diode shows dynamic LC oscillation behavior under a constant DC voltage, connected to an external inductor. From p-WSe2/n-MoOx oxide diode, similar NDR behavior to those of p-MoTe2/n-HAT-CN is again observed along with LC oscillations. The authors attribute these visible oscillation results to high peak-to-valley current ratios of their organic or oxide/2D heterojunction diodes. 相似文献
98.
Jiwoo Min Jaemin Im Seung Hyun Kim Hyun Ho Choi Kilwon Cho 《Advanced functional materials》2023,33(19):2212825
Molecular doping in conjugated polymers (CPs) has recently received intensive attention for its potential to achieve high electrical conductivity in organic thermoelectric materials. In particular, it affects not only the carrier density n but also the carrier mobility µ because high degree of molecular doping changes the morphological properties. Herein, the effect of molecular doping in CP thin films on the pathways and mechanisms of charge transport is investigated, which govern the µ-n relationship. Two representative donor–acceptor type CPs with similar µ but different molecular assembly in an undoped state, that is poly[2,5-(2-octyldodecyl)-3,6-diketopyrrolopyrrole-alt-5,5-(2,5-di(thien-2-yl)thieno[3,2-b]thiophene)] (DPPDTT) and indacenodithiophene-co-benzothiadiazole (IDTBT), are prepared. Heavy doping with iron chloride (FeCl3) induced DPPDTT with highly crystalline edge-on orientation to increase its µ up to 19.6 cm2 V−1 s−1, whereas IDTBT with irregular intermolecular stacking showed little change in µ. It is revealed that this different µ-n relationship is highly attributed to the initial molecular ordering of CP films. The charge transport mechanism also becomes significantly different: both coherent and incoherent transports are observed in the doped DPPDTT, whereas incoherent transport is only found in the doped IDTBT. This study suggests guidelines for enhancing charge transport of CPs under doping in terms of structural disorder. 相似文献
99.
N. W. Kim G. Ataguba S. C. Joyner Chuangdian Zhao Hyejin Im 《Computer Graphics Forum》2023,42(3):323-335
Modern visualization software and programming libraries have made data visualization construction easier for everyone. However, the extent of accessibility design they support for blind and low-vision people is relatively unknown. It is also unclear how they can improve chart content accessibility beyond conventional alternative text and data tables. To address these issues, we examined the current accessibility features in popular visualization tools, revealing limited support for the standard accessibility methods and scarce support for chart content exploration. Next, we investigate two promising accessibility approaches that provide off-the-shelf solutions for chart content accessibility: structured navigation and conversational interaction. We present a comparative evaluation study and discuss what to consider when incorporating them into visualization tools. 相似文献
100.
Analyzing Research and Development (R&D) trends is important because it can influence future decisions regarding R&D direction. In typical trend analysis, topic or technology taxonomies are employed to compute the popularities of the topics or codes over time. Although it is simple and effective, the taxonomies are difficult to manage because new technologies are introduced rapidly. Therefore, recent studies exploit deep learning to extract pre-defined targets such as problems and solutions. Based on the recent advances in question answering (QA) using deep learning, we adopt a multi-turn QA model to extract problems and solutions from Korean R&D reports. With the previous research, we use the reports directly and analyze the difficulties in handling them using QA style on Information Extraction (IE) for sentence-level benchmark dataset. After investigating the characteristics of Korean R&D, we propose a model to deal with multiple and repeated appearances of targets in the reports. Accordingly, we propose a model that includes an algorithm with two novel modules and a prompt. A newly proposed methodology focuses on reformulating a question without a static template or pre-defined knowledge. We show the effectiveness of the proposed model using a Korean R&D report dataset that we constructed and presented an in-depth analysis of the benefits of the multi-turn QA model. 相似文献