Research on Export Sophistication, Efficiency, and Potential of Agriculture Product Trade between South Korea and RCEP Countries: Based on the Stochastic Frontier Gravity Model

Zhe Ma,지성태,Qingdao Agricultural University 한국무역학회 2024 Journal of Korea trade Vol.28 No.1

Purpose - This study examines the structure of agricultural export sophistication, export efficiency, and the potential of South Korea’s agricultural products for Regional Comprehensive Economic Partnership (RCEP) countries. Design/Methodology – This study evaluates the agricultural export sophistication of RCEP countries and investigate export sophistication’s effects on the efficiency and potential of South Korea’s agricultural exports to RCEP countries. To this end, we construct a stochastic frontier gravity model (SFGM) based on panel data of agricultural product trade and other factors that impact agricultural imports and exports between South Korea and 36 countries from 2001 to 2020. Using this “one-step method” trade inefficiency model, we evaluate the impact of export sophistication on export efficiency and potential and calculate trade efficiency and potential. Findings – The results reveal a growing trend in the structure of global and RCEP countries’ agricultural export sophistication where the export sophistication of the target countries positively impacts Korea’s agricultural exports to those nations. In addition, RCEP member countries accounted for 50% of the top ten countries in the 2020 trade efficiency ranking, and the average trade efficiency of RCEP member countries show an upward trend. Originality/value - South Korea is geographically close to most RCEP countries, which facilitates agricultural trade. Moreover, there are significant differences in climate conditions and resource endowments between South Korea and most RCEP countries, providing opportunities for expanding agricultural trade with these nations. This study contributes to the extant literature by further exploring the trade efficiency and potential of Korea’s agricultural exports to RCEP countries by considering export sophistication as an important potential factor affecting the competitiveness of Korea’s agricultural exports and analyzing the relationship between the structure of export sophistication and the trade efficiency of Korea’s agricultural product exports to RCEP members.

An Analysis of Female Narrative Voice in Alice Walker’s The Color Purple

Zhe Ma 한국동서비교문학학회 2020 동서 비교문학저널 Vol.0 No.54

As one of the famous modern American female writers, Alice Walker has created a lot of literary works including poetry, novels and short stories to reveal the black people’s demands of the rights in freedom, equality, religion and other aspects of whom the black women are the focused ones for their survival and fights. Therein, the novel The Color Purple is one of Walker’s outstanding works. Many scholars have explored more on the feminist consciousness and put the texts analysis aside while there are also some scholars discussing the narrative techniques of this novel without taking seriously the existence of feminist consciousness. Here, this novel is analyzed from the perspective of narrative voice in feminist narratology of Susan Lancer and Robin Warhol to interpret and discuss the protagonist Celie’s identity construction of female authority reflecting the effective combination of feminist criticism and narrative techniques analysis. Meanwhile, this thesis is aimed to reveal that Walker effectively eliminates the domination of male discourse and establishes her own female narrative authority, so as to make an attempt to understand the novel further and Walker’s creation intention.

Rebecca Walker’s Identity Seeking in Her Autobiography

Zhe Ma 한국동서비교문학학회 2020 동서 비교문학저널 Vol.0 No.52

In recent years, there are few researches on Rebecca Walker and her some works in literature review field. By the background of American multi-culture, on the basis of identity theory, started from protagonist’s growth confusion, this thesis analyzed the protagonist’s reasons of growth confusion, identity construction, the solutions to conflicts and final black identity return. One of the main purposes is to get readers have a better understanding about the real existence of multiple descent groups in the American multicultural context and also can help those multiple descent groups who are about to integrate into the American society have a certain reference. On the other hand, more and more parents in single-parent families can also learn the lessons and instructions to their children’s education from this thesis. The goal of the current study is the American multi-culture and the influences of American multi-culture. In conclusion, autobiographical literature works not only describes us the lives of individuals, but a reflection of the cultural background at that time.

Controlling the Precursor Morphology of Ni-rich Li(Ni0.8Co0.1Mn0.1)O2 Cathode for Lithium-ion Battery

Wen-Zhe Shen,Yi Ma,Yaochun Yao,Feng Liang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.8

Ni-rich Li(Ni0.8Co0.1Mn0.1)O2 cathode material is widely recognized as one of the most cathode materials for lithium-ion batteries due to its high specific capacity, high energy density and low cost. In this paper, the NCM cathode material precursor Ni0.8Co0.1Mn0.1(OH)2 was prepared by coprecipitation method and the optimum experimental conditions were investigated. The effects of water bath temperature on the electrochemical performances of the prepared materials were investigated by controlling the morphology. The results showed that 60 ℃ was the best bath temperature for the precursor which has a regular spheroidal morphology and uniform particles with the diameter of 10 μm. After coprecipitation, the samples calcined under oxygen atmosphere displayed good electrochemical properties. The discharge specific capacity is up to 194 mA · h · g -1 and 134 mA · h · g -1 at 0.2 ℃ and 5 ℃, respectively. The initial coulombic efficiency is 87.57% at 0.2 ℃.

Basic Fibroblast Growth Factor Increases Intracellular Magnesium Concentration through the Specific Signaling Pathways

Bing-Zhe Hong,박선아,Han-Na Kim,Tian-Ze Ma,Han-Gyu Kim,강형섭,김환규,곽용근 한국분자세포생물학회 2009 Molecules and cells Vol.28 No.1

Basic fibroblast growth factor (bFGF) plays an important role in angiogenesis. However, the underlying mechanisms are not clear. Mg2+ is the most abundant intracellular divalent cation in the body and plays critical roles in many cell functions. We investigated the effect of bFGF on the intracellular Mg2+ concentration ([Mg2+]i) in human umbilical vein endothelial cells (HUVECs). bFGF increased [Mg2+]i in a dose-dependent manner, independent of extracellular Mg2+. This bFGF-induced [Mg2+]i increase was blocked by tyrosine kinase inhibitors (tyrphostin A-23 and genistein), phosphatidylinositol 3-kinase (PI3K) inhibitors (wortmannin and LY294002) and a phospholipase Cγ (PLCγ) inhibitor (U73122). In contrast, mitogen-activated protein kinase inhibitors (SB202190 and PD98059) did not affect the bFGF-induced [Mg2+]i increase. These results suggest that bFGF increases the [Mg2+]i from the intracellular Mg2+ stores through the tyrosine kinase/PI3K/PLCγ- dependent signaling pathways.

Slide Session : OS-GAS-02 ; Gastroenterology : Application of Machine Learning Techniques for Clin-ical Predictive Modeling: A Cross-Sectional Study on Nonalcoholic Fatty Liver Disease

( Han Ma ),( Chengfu Xu ),( Zhe Shen ),( Chaohui Yu ),( Youming Li ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. Recent attention focuses on screening and prediction of NAFLD. Machine learning techniques are powerful and promising tools. Methods: A cross-sectional study was performed among 10,508 subjects who attended their annual health examination in the first affiliated hospital, College of Medicine, Zhejiang University, China in 2010. The questionnaires, Physical examinations, laboratory tests and liver ultrasonography were performed. 20 features (e.g., age, laboratory results) were extracted. Machine learning techniques were implemented on the open source software named Weka. The tasks included feature selection and classification. By removing redundant features, feature selection techniques built a screening model. Classification was used to build a prediction model, which was evaluated by F measure. Nine machine learning techniques were investigated, i.e., logistic regression, K-Nearest Neighbor, Support Vector Machine, naive Bayes, Bayesian network, decision tree, Adaboosting, bagging, and random forest. Results: A total of 2522(24%) subjects were fulfilled the diagnostic criteria of NAFLD. By using feature selection techniques, BMI, serum triglyceride, ALT, GGT and uric acid were the top-5 features contributing most to NAFLD. 10-fold cross-validation was used in classification to evaluate machine learning techniques, i.e., subjects were randomly divided into 10 folds, 9 folds were used to build a prediction model, the remaining fold was used to evaluate. The whole process lasted for 10 times, average performance was recorded. The results showed among the nine state-of-the-art machine learning techniques, Bayesian network demonstrated the best performance. It achieves the accuracy, specificity, sensitivity, and F-measure scores up to 83%, 0.787, 0.678, and 0.665, respectively. Compared with logistic regression, Bayesian network improves F-measure score by 10.83%. Conclusions: Novel machine learning techniques may have screening and predictive value for NAFLD.

AtMe : An Online Multi-tenant Social Networking Service in Campus

Kun Ma,Zijie Tang,Zhe Yang,Shuwei Yao 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.5

Recently, more and more undergraduates have turned Internet to find support and take part in society in campus. However, current SNS systems are not oriented to a specific campus. In this paper, we design an online multi-tenant social networking service in campus, including At Helper and At Society. At Helper aims at improving the success ratio of the help process with a multi-tenant architecture, and At Society provides social services using popular instant messaging mobile application. Both modules change the traditional operation and maintenance to rent services. Besides, the key innovative design, such as multi-tenancy and access-aware data cache, are discussed in detail.

Fabrication of Large Area Photonic Crystals with Periodic Defects by One-Step Holographic Lithography

Jie Ma,Kam Sing Wong,Shan Li,Zhe Chen,Jianying Zhou,Yongchun Zhong 한국광학회 2015 Current Optics and Photonics Vol.19 No.1

A one-step fabrication of a photonic crystal (PC) with functional defects is demonstrated. Using multi-beamphase-controlled holographic lithography with a diffracting optical element, large area one dimensional (1D)and two dimensional (2D) PCs with periodic defects were fabricated. The uniform area is up to 2 mm2,and tens of defect channels have been introduced in the 1D and 2D PC structure. This technique givesrise to substantial reduction in the fabrication complexity and significant improvement in the spatialaccuracy of introducing functional defects in photonic crystals. This method can also be used to designand fabricate three dimensional (3D) PCs with periodic defects.

Shear behavior of composite frame inner joints of SRRC column-steel beam subjected to cyclic loading

Hui Ma,Sanzhi Li,Zhe Li,Yunhe Liu,Jing Dong,Peng Zhang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.27 No.4

In this paper, cyclic loading tests on composite frame inner joints of steel-reinforced recycled concrete (SRRC) column.steel beam were conducted. The main objective of the test was to obtain the shear behavior and analyze the shear strength of the joints. The main design parameters in the test were recycled coarse aggregate (RCA) replacement percentage and axial compression ratio. The failure process, failure modes, hysteresis curves and strain characteristics of the joints were obtained, and the influences of design parameters on the shear strength of the joints have been also analysed in detail. Results show that the failure modes of the joints area are typical shear failure. The shear bearing capacity of the joints maximally decreased by 10.07% with the increase in the RCA replacement percentage, whereas the shear bearing capacity of the joints maximally increased by 16.6% with the increase in the axial compression ratio. A specific strain analysis suggests that the shear bearing capacity of the joints was mainly provided by the three shear elements of the recycled aggregate concrete (RAC) diagonal compression strut, steel webs and stirrups of the joint area. According to the shear mechanism and test results, the calculation formulas of the shear bearing capacity of the three main shear elements were deduced separately. Thus, the calculation model of the shear bearing capacity of the composite joints considering the adverse effects of the RCA replacement percentage was established through a superposition method. The calculated values of shear strength based on the calculation model were in good agreement with the test values. It indicates that the calculation method in this study can reasonably predict the shear bearing capacity of the composite frame inner joints of SRRC column–steel beam.

A Study on Control of Heater Power and Heating Time for Thermoforming

Zhen-Zhe Li,Guang Ma,Dong-Ji Xuan,Seoung-Yun Seol,Yun-De Shen 한국정밀공학회 2010 International Journal of Precision Engineering and Vol. No.

Obtaining a uniform thickness of the final product using thermoforming is difficult, and the thickness distribution depends strongly on the distribution of the sheet temperature. In this paper, the time-dependent temperature distribution of the total sheets in the storing stage was studied because the temperature after the storing stage is the initial temperature of the heating process. An analytic solution for simulating the storing stage was derived. Using the solved analytic solution, the time-dependent temperature distribution of the total sheets was found out under the condition of assuming that the temperature-dependent specific heat of the ABS sheets was a certain constant value. Finally, the control method for a successful thermoforming using the heater power or heating time was researched in order to improve the quality of the final products. The results show that the satisfied temperature distribution can be obtained by adjusting the heater power or heating time. The method for analysis in this study will be used to improve the quality of the final products.