Effects of Vanadium Content on the Microstructure and Dry Sand Abrasive Wear of a Eutectic Cr-Fe-C Hardfacing Alloy

Hsuan-Han Lai,Chih-Chun Hsieh,Chi-Ming Lin,Weite Wu 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.1

In this study, the effects of vanadium on the morphology and wear behavior of a eutectic Cr-Fe-C hardfacing alloy were discussed. The alloys tested contained different amounts of vanadium, ranging from 0 to 2.39 wt%. A fibrous V4C3 was found when the alloy contained 0.93 wt% vanadium. The addition of vanadium was found to decrease the fraction of eutectic M23C6 and increase the width of the interspaces between the eutectic cells. The DTA results revealed that V4C3 formed just before the eutectic α+M23C6 during solidification. The surface hardness was shown to increase with increasing vanadium content, which also caused the hardness deviation and wear loss to decrease; however, the addition of vanadium was not shown to affect the hardness of eutectic α+M23C6. The V4C3 could be scratched off during the wear test due to the increase in the width of the interspaces between the eutectic cells; therefore, the alloys that contained 0.93 and 2.39 wt% vanadium exhibited similar wear loss results.

Lattice Relations and Solidification of the Complex Regular Eutectic (Cr,Fe)-(Cr,Fe)23C6

Hsuan-Han Lai,Chih-Chun Hsieh,Chi-Ming Lin,Weite Wu 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.3

The eutectic (Cr,Fe)-(Cr,Fe)23C6 showed a triaxial fishbone structure and could be categorized as a “complexregular structure”. In this study, the lattice relations of the fishbone (Cr,Fe)23C6 were examined and the solidificationprocess was observed using a transmission electron microscope and a confocal laser scanning microscope. Forone of the three fish bones in a eutectic cell, parallel (Cr,Fe)23C6 lamellas at one side of the spine had the samelattice direction, as did those in the (Cr,Fe) phase. The lattices of neighboring (Cr,Fe)23C6 and (Cr,Fe) phases werenot coherent. Lamellar (Cr,Fe)23C6 on opposite sides of a spine had different lattice directions, and their latticeboundary was in the spine. By using the confocal laser scanning microscope, the solidification of lamellar eutecticstructure could be observed. At the low cooling rate of 5oC·min-1, parallel lamellas would grow thick blocksinstead of thin plates. To obtain a thin lamellar eutectic structure, the cooling rate should be higher, likethe rate in welding.

Genetic Algorithm for Shortest Driving Time in Intelligent Transportation Systems

Chu-Hsing Lin,Jung-Chun Liu,Chia-Han Ho,Jui-Ling Yu,Wei-Shen Lai 보안공학연구지원센터 2009 International Journal of Hybrid Information Techno Vol.2 No.1

The route guidance system, which provides driving advice based on traffic information about an origin and a destination, has become very popular along with the advancement of handheld devices and the global position system. Since the accuracy and efficiency of route guidance depend on the accuracy of the traffic conditions, the route guidance system needs to include more variables in calculation, such as real time traffic flows and allowable vehicle speeds. As variables considered by the route guidance system increase, the cost to compute multiplies. Since handheld devices have limited resources, it is not feasible to use them to compute the exact optimal solutions in real time systems by some well-known algorithm, such as the Dijkstra’s algorithm, which is usually used to find the shortest path with a map of reasonable numbers of vertices. To solve this problem, we propose to use the genetic algorithm to alleviate the rising computational cost. We use the genetic algorithm to find the shortest time in driving with diverse scenarios of real traffic conditions and varying vehicle speeds. The effectiveness of the genetic algorithm is clearly demonstrated when applied on a real map of modern city with very large vertex numbers.

중국 전자상거래 기업의 제3자 물류기업 선택 기준과 평가에 관한 연구

판리리(Fan Li li),우수한(Su Han Woo),Po Lin Lai 한국국제상학회 2016 國際商學 Vol.31 No.2

본 연구에서는 최근 급격히 증가하고 있는 중국 전자상거래에서 제3자 물류기업 선정기준을 AHP(Analytic Hierarchy Process)기법을 사용하여 각 평가요인들의 상대적 중요도를 도출하고자 한다. 선정을 위한 요인으로 1단계에는 가격, 물류서비스, 편리성, 기업역량의 4가지 항목을 두었고, 2단계에는 가격경쟁력, 가격세분화, 정보제공, 신속성, 안전성, 접근성, 다양성, 재무안전성, 파트너쉽을 두었다. 3단계는 중국의 주요 물류기업인 Deppon express, S.F. Express, STO express, 우정국택배, CNEX의 5개 물류기업을 물류기업 선정의 대안으로 설정하였다. 이를 평가하기 위하여 중국의 전자상거래기업과 일반제조기업으로 나누어 설문조사를 실시하였다. 분석결과를 제3자 물류기업의 선정요인의 우선순위는 가격, 물류서비스, 편리성, 기업역량 순서로 평가되어 가격과 물류서비스의 중요도가 특히 높은 것으로 나타났다. SF Express가 가장 경쟁력있는 것으로 평가되었는데, 두 그룹간에는 조금의 차이가 발생했다. 전자상거래 기업은 SF Express를 선호한 반면, 일반 제조기업들은 Deppon Express를 선호하였다. Purpose : This paper evaluates the relative importance of selection criteria on 3PL logistics companies from Chinese e-business companies’ viewpoints. Research design, data, methodology : Analytic Hierarchy Process(AHP) is employed to fulfill the objective of this paper using price, logistics services, convenience and firm competency as the first-level criteria. In addition major 3PL companies in China are evaluated based on the criteria and their importance such as Deppon Express, S.F. Express, STO express, China EMS, CNEX. Data are collected from E-business firms and manufacturers in China for comparison purpose. Results : The results suggest that price is considered the most important and there is no significant difference between E-business firms and manufacturers. SF Express is evaluated the highest, but manufacturers prefers Deppon Express whereas SF express is preferred by E-business firms. Conclusion : This paper shows that price factor has the most important role in logistics company selection in E-business as well as manufacturing industry.

Predatory efficacy of Orius strigicollis (Hemiptera: Anthocoridae) against Tetranychus urticae (Acarina: Tetranychidae) on strawberry

Shu-Jen Tuan,Yung-Hsiang Lin,Shu-Chen Peng,Wei-Han Lai 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.1

In this study, the predatory efficacy of Orius strigicollis (Poppius), a predacious flower bug, against the twospotted spider mite (TSSM), Tetranychus urticae Koch, on strawberry (Fragaria ananassa) was investigated. Our results showed that release of 2, 4, 6, and 12 neonates of O. strigicollis per strawberry plant could suppress 58.9, 72.6, 88.6, and 92.8% of T. urticae, respectively, at 14 days after treatment. A single release of 12 neonate bugs per plant achieved and maintained, over a period of 3 months, 82% to 98% control of T. urticae population. A biweekly release of 6 neonate bugs per plant; likewise, suppressed ca. 90% of T. urticae population throughout the same period. However, predatory efficacy was reduced by an over-release of predators which may cause cannibalism as well as lower possibility of finding prey. Since the released neonates survived well to adults with offspring that retained their predatory ability, this study has demonstrated that O. strigicollis is a predatorwith good potential for sustainable suppression of T. urticae on strawberry, and one application of O. strigicollis neonates at a predator:prey ratio of 1:200 egg plus motile TSSM or 1:60 motiles per strawberry plant promises a season-long control and substantial management of spider mite infestation.

Anomaly Detection Using LibSVM Training Tools

Jung-Chun Liu,Chu-Hsing Lin,Jui-Ling Yu,Wei-Shen Lai,Chia-Han Ho 보안공학연구지원센터 2008 International Journal of Security and Its Applicat Vol.2 No.4

Intrusion detection is the means to identify the intrusive behaviors and provide useful information to intruded systems to respond fast and to avoid or reduce damages. In recent years, learning machine technology is often used as a detection method in anomaly detection. In this research, we use support vector machine as a learning method for anomaly detection, and use LibSVM as the support vector machine tool. By using this tool, we get rid of numerous and complex operations and do not have to use external tools for finding parameters as needed by using other algorithms such as the genetic algorithm. Experimental results show that high average detection rates and low average false positive rates in anomaly detection are achieved by our proposed approach.

Weight Gain in Pregnancy, Maternal Age and Gestational Age in Relation to Fetal Macrosomia

( Yi Li ),( Qi-fei Liu ),( Dan Zhang ),( Ying Shen ),( Kui Ye ),( Han-lin Lai ),( Hai-qing Wang ),( Chuan-lai Hu ),( Qi-hong Zhao ),( Li Li ) 한국임상영양학회 2015 Clinical Nutrition Research Vol.4 No.2

To investigate the possible risk factors related to macrosomia. Pregnant women and their newborns (n = 1041) were recruited from a cohort study in Maternal and Child Care Center of Hefei from January 2011 to July 2012. Questionnaires were applied to collect the demographic data besides the medical records. Detailed health records of the entire pregnancy were obtained using retrospective study. Meanwhile the data of neonatal outcomes was prospectively tracked. Associations between exposure risk factors and macrosomia were analyzed using Pearson’s chi squared test. Logistic regression models were used to assess the independent association between these potential predictors and macrosomia. The incidence of macrosomia of this cohort was 11.24% of which male: female = 2.55:1. Male incidence (8.07%) of macrosomia was higher than female (3.17%), p < 0.001. Body mass index (BMI) before pregnancy (pre-BMI), maternal height, parity were not independently associated with macrosomia; multiple logistic regression analysis indicated that macrosomia was mainly independently associated with weight gain in pregnancy (OR=1.14,95% CI [1.10-1.19]), maternal age (OR = 1.09,95% CI [1.03-1.15]) and gestational age (OR = 1.62,95% CI [1.31-1.99]), respectively. Our findings indicate that weight gain in pregnancy, maternal age and gestational age should be considered as independent risk factors for macrosomia.