Evaluation of automotive weatherstrip by coupled analysis of fluid-structure-noise interaction

Automotive weatherstrip plays a major role in isolating the passenger compartment from water, dust and noise, etc. Among them, the wind noise through weatherstrip is the most severe factor making the passenger uncomfortable. Weatherstrip should be in contact between the door and the body frame, and sufficient contact area is needed to minimize the wind noise through weatherstrip. But there are several factors that make it difficult to ensure sufficient contact area. First, weatherstrip rubber deteriorates as time goes by and residual stress in the rubber becomes relaxed which results in the decrease of the contact area. Second, the gap between the door and the body increases due to pressure difference at high speed. In order to predict and reduce wind noise through weatherstrip, nonlinear behaviour of rubber at high speed and he effect of rubber deformation to wind noise should both be analyzed. In the paper, rubber deformation with time is obtained by hyperelastic and viscoelastic analyses, while the gap between the door and the body frame of the vehicle going at a high speed was predicted by the coupled analysis, Fluid-Structure Interaction (FSI). And also Statistical Energy Analysis (SEA) calculates the amount of wind noise numerically caused by rubber deformation under high speed condition

A TEXT MINING APPROACH TO THE ANALYSIS OF INFORMATION SECURITY AWARENESS: KOREA, UNITED STATES, AND CHINA

Recently in Korea, the importance of information security awareness has been receiving a growing attention. Attacks such as social engineering and ransomware are hard to prevent because it cannot be solved by information security technology. Also, the profitability of information security industry has been decreasing for years. Because of this, many companies try to find a new growth-engine and an entry to the foreign market. The main purpose of this paper is to draw out some information security issues that people of each country think and to analyze it. Finally, this study identifies issues and suggests how to improve the situation in Korea. For this, Topic Modeling analysis has been used to find information security issues of each country. Moreover, the score of sentiment analysis has been used to compare each country. The study contributes to the literature by exploring and explaining what critical issues are and how to improve the situation based on the identified issues of the Korean information security industry. Also, this study adds to the literature by demonstrating how text mining can be applied to the context of information security awareness. From a pragmatic perspective, the study has the implications for information security enterprises. This study is expected to provide a new and realistic method of analyzing domestic and foreign issues using the analyzing real data of the Twitter API

Combinatorial growth of Si nanoribbons

Silicon nanoribbons (Si NRs) with a thickness of about 30 nm and a width up to a few micrometers were synthesized. Systematic observations indicate that Si NRs evolve via the following sequences: the growth of basal nanowires assisted with a Pt catalyst by a vapor-liquid-solid (VLS) mechanism, followed by the formation of saw-like edges on the basal nanowires and the planar filling of those edges by a vapor-solid (VS) mechanism. Si NRs have twins along the longitudinal < 110 > growth of the basal nanowires that also extend in < 112 > direction to edge of NRs. These twins appear to drive the lateral growth by a reentrant twin mechanism. These twins also create a mirror-like crystallographic configuration in the anisotropic surface energy state and appear to further drive lateral saw-like edge growth in the < 112 > direction. These outcomes indicate that the Si NRs are grown by a combination of the two mechanisms of a Pt-catalyst-assisted VLS mechanism for longitudinal growth and a twin-assisted VS mechanism for lateral growth

Primary Pulmonary Plasmacytoma Presenting as Multiple Lung Nodules

Extramedullary plasmacytoma is a plasma cell tumor arising outside the bone marrow and usually occurs as a solitary tumor in the upper respiratory tract, such as the pharynx, paranasal sinuses, nasal cavity, or oral cavity [1]. Other cases develop in the lymph nodes, skin, gastrointestinal tract, genitourinary tract, and other regions. Primary pulmonary plasmacytomas are very rare and usually present as solitary lung nodules or masses [2]. Unusual cases manifest as diffuse pulmonary infiltration [3,4]. We describe here a unique case of primary pulmonary plasmacytoma, which presented as multiple lung nodules during regular screening in a patient with systemic lupus erythematosus

Geographic variation and factors associated with rates of knee arthroplasty in Korea-a population based ecological study

Background The recent increase in knee arthroplasty (KA) use in Korea is among the highest in the world. The rapid increase in KA use suggests that the KA use in Korea could have been affected by medically unjustifiable factors. This study aimed to examine the geographic variation in the rate of KA and its associated factors in Korea. Methods We used the data from the National Health Insurance in Korea in 2013, from which a total of 67,086 claims for KA were obtained. We calculated the age-sex-standardized KA rates of the entire population and the crude rates of the age groups 0–64 and 65 and over in 251 districts. We assessed the geographic variation of the KA rates and examined the associated factors with a multivariate linear regression with the KA rate as a dependent variable. Results The overall rate of KA in Korea was 132.7 per 100,000 persons. The rates of KA showed a four-fold variation. The deprivation index score and the number of beds in the small to medium sized hospitals showed a positive association with the rates of KA while the number of orthopedic surgeons showed a negative association. Conclusions Korea has been experiencing a rapid increase in the use of KA for the last decade or so, which was most prominent among the elderly population aged 65 and older. Our results suggest that the higher rate of KA is strongly related to a higher supply of beds and the socioeconomically deprived conditions. Considering that the decision concerning KA has room for discretion and also affects a considerable portion of health care expenditures, the use of KA should be thoroughly monitored with more emphasis on standardization in the decision making process and preventive measures that can lessen the need for KA.This work was supported by the National Health Insurance Service in Korea. The funding source had no role in study design, data analysis, or data interpretation

Blockchain and AI Meet in the Metaverse

With new technologies related to the development of computers, graphics, and hardware, the virtual world has become a reality. As COVID-19 spreads around the world, the demand for virtual reality increases, and the industry represented by the Metaverse is developing. In the Metaverse, a virtual world that transcends reality, artificial intelligence and blockchain technology are being combined. This chapter explains how artificial intelligence and blockchain can affect the Metaverse