Effects of Si on the Microstructure and Work Hardening Behavior of Fe‒17Mn‒1.1C‒xSi High Manganese Steels

Renlong Xiong,Yi Liu,Haitao Si,Huabei Peng,Shanling Wang,Binhan Sun,Hanxin Chen,Hyoung Seop Kim,Yuhua Wen 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

In order to improve the work hardening capacity under low stresses and the yield strength of conventional Hadfield steels, theeffects of Si on the microstructure and work hardening behavior of the Fe‒17Mn‒1.1C‒xSi steels under both quasi-statictensile and low load impact are investigated. It is shown that the increase of the Si contents remarkably improves the yieldstrength by 36 MPa per 1 wt% Si in the investigated steel system without significant sacrifice of ductility. The decreasingeffect of Si on the stacking fault energy is strongly affected by carbon, although the variation of carbon content was small. This led to the unexpected similar stacking fault energy between 1Si and 2Si steel. With the increase of the Si contents forthe steels, the critical strain for the onset of mechanical twinning was lowered, which was controlled by the cooperationbetween the stacking fault energy and solid solution strengthening of Si. This resulted in the earlier initiation of mechanicaltwins and an increase in the twin volume fraction. Therefore, the work hardening capacities under both quasi-static tensileand low load impact tests were enhanced. It was also found that the impact deformation decreased as more mechanical twinsabsorbed the impact energy.

Early Recognition of Pediatric Strokes in the Emergency Department: Epidemiology, Clinical Presentation, and Factors Impeding Stroke Diagnosis in Children

Si Qi Tan(Si Qi Tan),Wen Qi Cher(Wen Qi Cher),Shu-Ling Chong(Shu-Ling Chong),Angelina Su Yin Ang(Angelina Su Yin Ang ),Sashikumar Ganapathy(Sashikumar Ganapathy ),Derrick Wei Shih Chan(Derrick Wei Shi 대한소아신경학회 2022 대한소아신경학회지 Vol.31 No.1

Purpose: Strokes are challenging to diagnose in pediatric emergency departments (EDs) as level of suspicion is low and atypical presentations are common. We analyzed clinical features, epidemiology and factors of delayed identification in arterial ischemic strokes (AIS) and hemorrhagic strokes (HS). Methods: Single-center retrospective cohort study of children aged between 29 days and 18 years old diagnosed with stroke between July 2016 to June 2021. Results: Among 36 children, 11 (30.5%) had AIS, 25 (69.4%) had HS. Median age for AIS was 9 years (interquartile range [IQR], 2 to 9) and HS 9 years (IQR, 1 to 11.5) (P=0.715). Focal neurological deficit was seen in 72.7% of AIS and 20% of HS (P=0.006). Only 18.2% of AIS and 52.0% of HS presented within 6 hours of symptoms. Median time from symptom onset to ED presentation was 24 hours (IQR, 12 to 28) for AIS and 7 hours (IQR, 1.8 to 48) for HS (P=0.595). Most (85.6%) arrived by own transport. Median time from presentation to neuroimaging was 7 hours (IQR, 0.9 to 7) for AIS and 4.8 (IQR, 1.3 to 16.8) hours for HS (P=0.376). Eleven patients, 9/25 (36.0%) HS and 2/11 (18.2%) AIS, did not have stroke as differential diagnosis at ED (P=0.714). Common initial diagnoses were viral illness or headaches. On univariate analysis, age <1 (odds ratio [OR], 17.5; 95% confidence interval [CI], 1.2 to 250.4; P=0.035) and absence of focal neurological deficit (OR, 13.091; 95% CI, 1.5 to 117.9; P=0.022) were significant factors for delayed identification. Conclusion: Index of suspicion for pediatric strokes among caregivers and clinicians should be increased. Public awareness campaigns are recommended.

ADPRT Val762Ala and XRCC1 Arg194Trp Polymorphisms and Risk of Gastric Cancer in Sichuan of China

Wen, Yuan-Yuan,Pan, Xiong-Fei,Loh, Marie,Tian, Zhi,Yang, Shu-Juan,Lv, Si-Han,Huang, Wen-Zhi,Huang, He,Xie, Yao,Soong, Richie,Yang, Chun-Xia Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: Gastric cancer remains a major health problem in China. We hypothesized that XRCC1 Arg194Trp and ADPRT Val762Ala may be associated with risk. Methods: We designed a multicenter 1:1 matched case-control study of 307 pairs of gastric cancers and controls between October 2010 and August 2011. XRCC1 Arg194Trp and ADPRT Val762Ala were sequenced, and demographic data as well as lifestyle factors were collected using a self-designed questionnaire. Results: Individuals carrying XRCC1 Trp/Trp or Arg/Trp variant genotype had a significantly increased risk of gastric cancer (OR, 1.718; 95% CI, 1.190-2.479), while the OR for ADPRT Val762Ala variant genotype (Ala/Ala or Val/Ala) was 1.175 (95% CI, 0.796-1.737). No gene-gene or gene-environment interactions were found. In addition, family history of cancer and drinkers proportion were higher among cases than among controls (P<0.05). Conclusions: XRCC1 194 Arg/Trp or Trp/Trp genotype, family history of cancer, and drinking are suspected risk factors of gastric cancer from our study. Our findings may offer insight into further similar large gene-environment and gene-gene studies in this region.

Comparison of Quality Property and Functionality among Beef Jerky made from Hanwoo, Australian and New Zealand beef

Wen-Si Hu,Eun Seon Ha,Soo-Jung Lee,Jae-Sung Kim,Nak-Ju Sung 한국식품영양과학회 2015 한국식품영양과학회 학술대회발표집 Vol.2015 No.8

Research on the Impact of Logistics Industry Efficiency and Agglomeration Effect on Import and Export Trade in Korea

Wen-Si Cheng 한국무역학회 2021 Journal of Korea trade Vol.25 No.5

Purpose – The logistics industry is often featured by its location relevance and industrial concentration. Industrial concentration is conducive to the effective transmission of information by reducing transaction costs and improving transaction efficiency, thus promoting the development of trade. The main purpose of this paper is to measure the spatial total factor productivity and location quotient of the logistics industry in Korea, and to study the impact of the logistics industry efficiency and agglomeration effect on import and export trade in Korea. Design/methodology – First, used the spatial stochastic frontier method to measure the spatial total factor productivity of the logistics industry in Korea, this serves as the efficiency index of the logistics industry in various regions of Korea. Second, calculated the location quotient (LQ) of the logistics industry to measure the industry’s concentration degree. Third, employed a spatial econometric model to analyze the impacts of factors such as the efficiency and concentration levels of the logistics industry on import and export trade in Korea. Findings – This study’s main findings can be summarized as follows: this study found that the overall efficiency of the logistics industry in Korea needs to be improved, even though it showed an upward trend in all regions of the country; Moreover, the agglomeration level of Korea’s logistics industry needs to be improved; Finally, the positive spatial correlation and industrial agglomeration effect of Korea s logistics industry had a positive impact on the country’s import and export trade. Originality/value – This study is innovative in terms of research perspective and methods. Most of the previous studies have measured the development level of the logistics industry using the logistics performance index (LPI), Fewer studies have assessed through the spatial total factor productivity and location quotient of the logistics industry in Korea to measure the efficiency index of the logistics industry in various regions of Korea and concentration degree, as well as there was almost no study on the impact of logistics industry efficiency and agglomeration effect on import and export trade in Korea. This study addresses this limitation by analyzing the impacts of the efficiency and agglomeration effect of the logistics industry on import and export trade in Korea.

Adaptive Neural Dynamic Surface Control for a General Class of Stochastic Nonlinear Systems with Time Delays and Input Dead-zone

Wen-Jie Si,Xun-De Dong,Fei-Fei Yang 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.5

This paper investigates adaptive tracking control for a more general class of stochastic nonlinear timedelaysystems with unknown input dead-zone. For the considered system, the drift and diffusion terms containtime-delay state variables. In control design, Lyapunov-Krasovskii functionals are employed to handle unknowntime-delay terms. Then, unknown nonlinear functions are approximated by RBF neural networks, and the dynamicsurface control (DSC) technique is utilized to avoid the problem of explosion of complexity. At last, based onthe Lyapunov stability theory, a robust adaptive controller is designed to guarantee that all closed-loop signals arebounded in probability and the tracking error converges to a small neighborhood of the origin. The simulationexample is presented to further show the effectiveness of the proposed approach.

The Effects of Foreign Currency Derivatives on the Monetary Policy Exchange Rate Channel in China

Wen Si 한국국제경제학회 2015 International Economic Journal Vol.29 No.2

This paper examines changes in the monetary policy exchange rate channel in the presence of foreign currency derivatives (FCD) markets in China. Initially a theoretical macroeconomics model incorporating the exchange rate risk hedging is presented, and this is followed by an empirical test. A theoretical model implies that with more firms using foreign currency derivatives to hedge the exchange rate risk, the effect of the exchange rate on the net exports will be weaker and may even be reversed. The empirical section uses Structure Vector Autoregression (SVAR) models with China's monthly macro data over the 2000–2013 period to assess the impact of the FCD market on the exchange rate channel. Empirical support for the changes in the exchange rate channel transmission is found. By impulse response function (IRF) analysis, with the emergence of the domestic FCD market in China, in the long run the probability becomes higher that the negative effect of RMB appreciation on China's net exports to the US is reversed; meanwhile the negative effects of RMB appreciation on the overall net exports and the net exports to the EU become gradually weaker on average.

Research on Service Component Retrieval with Hadoop

Wen Si,Rong Tan,Lu Bing 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.10

It remains both important and difficult for service-oriented computing to retrieve accurately and efficiently the service components fulfilling the client’s need. This paper intends to present a method for use in retrieving the personalized service components based on Hadoop architecture. It extends the semantic ontology of service components, and proposes the methods for building and inquiring the index files based on Lucene. By utilizing the HDFS and adopting the QoS computation and personalized recommendation techniques, the working principles of Map and Reduce of Hadoop are expanded. Experiment results show that the proposed method is applicable in realizing the retrieval of service components in distributed computing environment.

A Proposed Scheme for City Family Health Information System

Wen Si,Hong-hao Gao,Xue-yi Li 보안공학연구지원센터 2014 International Journal of Smart Home Vol.8 No.3

A Comparative Study on the Export Potential of the Digital Service Trade between China and Korea: Based on RCEP Country Data

Wen-Si Cheng 한국무역학회 2023 Journal of Korea trade Vol.27 No.2

Purpose – The digital service trade has become an important driver of the global service trade. The main purpose of this study is to explore the influencing factors of digital service exports from China and Korea to RCEP sample countries respectively, and to comprehensively study the export potential of China and Korea to RCEP countries, so as to provide theoretical guidance and a decision-making reference to promote digital service trade exports and digital economy development in China and Korea. Design/methodology – First, the stochastic frontier gravity model was improved by introducing nonefficiency factors affecting digital services trade, extending the gravity model of traditional services trade exports to digital services trade exports. Secondly, the panel data of China and Korea for the eight sample countries of RCEP from 2011 to 2021 were adopted for the empirical analysis of digital service export potential by a stochastic frontier model. Findings – China's economic growth plays a role in increasing China's digital service trade exports, while Korea's economic growth does not play a significant role in increasing Korea's digital service trade exports. However, the economic growth of trading partner countries can play a significant role in boosting the digital service trade in both China and Korea, and comparison shows that Korea has higher resilience in the digital services trade than China. In addition, the market size of target countries plays a positive role in promoting the digital service trade exports of both China and Korea, and the increase in the value-added share of services in target countries will lead to a decrease in the digital service trade exports of both China and Korea. Originality/value – This study is innovative in terms of research perspective and method. Academic research on the export potential of international trade has been extensive, but most studies are based on the perspective of the goods trade, fewer studies are based on the perspective of the service trade, and there are almost no studies based on the perspective of digital service trade. There is a gap based on the comparative analysis of the export potential of the digital service trade between China and Korea. This study extends the gravitational model of traditional service trade exports to digital service trade exports to comparatively analyze the export potential of China and Korea to RCEP countries. This study addresses this limitation by analyzing a comparative analysis of the digital service trade export potential of China and Korea.