Computer simulation for stability performance of sandwich annular system via adaptive tuned deep learning neural network optimization

Ming, Yan,Zandi, Yousef,Gholizadeh, Morteza,Oslub, Khaled,Khadimallah, Mohamed Amine,Issakhov, Alibek Techno-Press 2021 Advances in nano research Vol.11 No.1

In this article with the aid of adaptively tuned deep neural network (DNN), dynamic stability analysis of the sandwich structure has been investigated. Due to finding the design-points features, the numerical solution procedure called two-dimensional generalized differential quadrature technique has been applied to the ordinary differential equations of the current structure system acquired on the foundation of the kinematic theory with refined higher order terms. Also, the involved parameters with the optimum values in the fully-connected neural network mechanism are obtained via momentum-based optimizer. For modeling a moderately thick structure, higher order terms of shear deformation are chosen. For stability analysis of the current structure the design points considering the method of adaptive learning is presented. For analysis of the current structure 'accuracy (used for determining the design-points) is presented through than the published outcomes in the literature. The outcomes of accuracy section of the current research show that the DNN-based model in analysis of the sandwich structure has less error than other models. The results show that the current momentum-based optimizer can be good tool for future researches about stability analysis of the various structure due to its good accuracy.

LC-MS/MS-based Quantification of Ten Neurotransmitters in Rat Limbic System and Serum: Application to Chronic Unpredictable Mild Stress- Induced Depression Rats

Mingyan Ma,Qiangxiang Chen,Wen Cao,Yubo Zhou,Aijuan Yan,Yanru Zhu 사단법인 한국질량분석학회 2023 Mass spectrometry letters Vol.14 No.3

As one of the most common mood disorders, numerous studies have shown depression is the main risk factor for non-suicidal self-harm. The pathogenesis of depression is complex, and a comprehensive and rapid measurement of monoamine neurotransmitters and their metabolites will be very helpful in understanding the pathogenesis of depression. Therefore, a rapid and sensitive underivatized liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous monitoring of the levels of ten neurotransmitters and their metabolites in rat serum and limbic system and success- fully applied to quantify the changes of neurotransmitter levels in chronic unpredictable mild stress-induced rats. The analytes studied were mainly involved in tyrosine metabolism, tryptophan metabolism, and glutamate cycling pathways, which are important in the pathogenesis of depression. It had been verified the method was sensitive and effective, with satisfactory linear- ity, and met the requirements of biological sample determination. Levels of neurotransmitters in rat serum, hippocampus, amyg- dala, prefrontal cortex, striatum, and hypothalamus were determined via the method. The results showed serotonin, dopamine, norepinephrine, and their metabolites were decreased, glutamine was increased, and glutamate was disturbed in chronic unpre- dictable mild stress-induced depression rats. This method provides a new approach to studying the pathogenesis of depression and other neurological disorders.

2-D meso-scale complex fracture modeling of concrete with embedded cohesive elements

Mingyan Shen,Zheng Shi,Chao Zhao,Xingu Zhong,Bo Liu,Xiaojuan Shu 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.3

This paper has presented an effective and accurate meso-scale finite element model for simulating the fracture process of concrete under compression-shear loading. In the proposed model, concrete is parted into four important phases: aggregates, cement matrix, interfacial transition zone (ITZ), and the initial defects. Aggregate particles were modelled as randomly distributed polygons with a varying size according to the sieve curve developed by Fuller and Thompson. With regard to initial defects, only voids are considered. Cohesive elements with zero thickness are inserted into the initial mesh of cement matrix and along the interface between aggregate and cement matrix to simulate the cracking process of concrete. The constitutive model provided by ABAQUS is modified based on Wang’s experiment and used to describe the failure behaviour of cohesive elements. User defined programs for aggregate delivery, cohesive element insertion and modified facture constitutive model are developed based on Python language, and embedded into the commercial FEM package ABAQUS. The effectiveness and accuracy of the proposed model are firstly identified by comparing the numerical results with the experimental ones, and then it is used to investigate the effect of meso-structure on the macro behavior of concrete. The shear strength of concrete under different pressures is also involved in this study, which could provide a reference for the macroscopic simulation of concrete component under shear force.

Research on the establishment of a theoretical model of empathy between the MOBA game “PLEX” and the players

Mingyan Feng,DongMin Cho,ChanSeok Hong 한국디자인학회 2021 한국디자인학회 학술발표대회 논문집 Vol.2021 No.11

空間活動保險法律問題及中國狀況:基於空間商業化最新發展的分析

섭명암 ( Mingyan Nie ) 한국항공우주정책·법학회(구 한국항공우주법학회) 2017 한국항공우주정책·법학회지 Vol.32 No.1

空間活動保險可以簡單的總結爲衛星保險、宇航員保險以及空間活動第三方責任險三種類型。在空間商業化尤其是空間私營化快速發展的大背景下,現有的有關空間活動保險的國際和國內法律制度面臨著挑戰。作爲一個正在加大力度發展本國空間商業活動的空間大國,中國的有關空間保險的法律規定値得討論。 現階段,有關衛星保險的制度發展良好,相關保險公司有能力爲衛星提供“發射前保險”,“發射階段保險”以及“衛星在軌保險”。中國於1997年成立的“中國航天保險聯合體”則致力於爲中國衛星發射提供保險。但是,隨著越來越多的私營實體參與到空間以及衛星工業活動之中,有必要對在“中國航天保險聯合體”?架下建立的諸多制度進行相應的調整。同時,應該進一步加强保險經紀人在私人空間及衛星活動中的作用。 宇航員被視爲人類派往外空的使者,幷且相關的國際法律規範中已經明確確定了宇航員的法律地位幷且要求各締約國對於處在緊急狀況下的宇航員予以必要的協助。從國內法的角度看,相關政府會爲宇航員購買全額保險。中國人壽保險公司爲宇航員創設了特種類型的“宇航員團體保險”,在不同時段爲宇航員提供階梯式保額。但是,値得注意的是,一旦外空旅遊發展爲一個産業,則有必要關注專門針對外空遊客的保險制度。爲了促進中國國內外空旅遊業的發展,建議將中國人壽保險公司創制的“宇航員團體保險”作爲一個可選模式提供給外空遊客。尤其是如果這些遊客是政府擁有的外空旅遊公司的客戶的情形下。而當私人實體開始參與提供軌道包括亞軌道旅遊服務,則需要重新考慮制定相應的有關外空遊客的保險制度。 一般而言,獲得一分第三方責任保險是申請人獲得空間物體發射許可證的必要條件。國內法中也會規定空間物體發射許可證申請人購買第三方責任險的義務。 中國2002年“民用航天發射項目許可證管理暫行辦法”意識到了第三方責任險的重要意義,規定許可證持有人在相應空間發射項目進入發射場之前購買第三方責任保險。這一規定與許多國家的做法存在差異。考慮到中國是亞洲地區唯一一個政府間空間合作組織,卽亞太空間合作組織的東道國,爲了促進未來的商業空間合作,有必要考慮對不同國家國內空間法進行協調的問題。 Insurances of space activities are divided into satellite insurance, astronaut insurance and third party liability insurance. Against the background of the rapid development of space commercialization, especially the increasing participation of private entities in space affairs, the present international and domestic mechanisms of space insurance are challenged. As a space-faring state which is in the process of developing space businesses, the regulations of space insurance in China are deserved to be discussed. Satellites insurance is at present well-developed, the “pre-launch”, “launch” and “in-orbit” phases of satellites are all possible to be insured by related companies. China created the CAIA in 1997 to provide insurance for Chinese satellites. However, with more private entities start to involve in space as well as satellite industry, the regime established under the framework of CAIA is necessary to be modified, and the mechanism relating to space insurance brokers should be promoted. The astronauts are recognized as the envoy of humankind, and relevant international regulations are made to provide assistance to them in emergency circumstances. From the domestic perspective, astronauts will be fully insured. China creates a particular type of insurance for astronauts. However, once space tourism becomes a business, the insurance of the tourist will be demanded to be created. In order to promote China`s space tourism, it is recommended to take the “Astronaut Group Insurance” as an optional model to space tourists, if the tourists are customers of a governmental-owned space company. Once private involvement of providing orbital/suborbital tourism service becomes a reality, new rules are required. Getting a third party liability insurance is deemed as an indispensable precondition for an applicant to get a launch permission. Domestic space laws will include Insurances of space activities are divided into satellite insurance, astronaut insurance and third party liability insurance. Against the background of the rapid development of space commercialization, especially the increasing participation of private entities in space affairs, the present international and domestic mechanisms of space insurance are challenged. As a space-faring state which is in the process of developing space businesses, the regulations of space insurance in China are deserved to be discussed. Satellites insurance is at present well-developed, the “pre-launch”, “launch” and “in-orbit” phases of satellites are all possible to be insured by related companies. China created the CAIA in 1997 to provide insurance for Chinese satellites. However, with more private entities start to involve in space as well as satellite industry, the regime established under the framework of CAIA is necessary to be modified, and the mechanism relating to space insurance brokers should be promoted. The astronauts are recognized as the envoy of humankind, and relevant international regulations are made to provide assistance to them in emergency circumstances. From the domestic perspective, astronauts will be fully insured. China creates a particular type of insurance for astronauts. However, once space tourism becomes a business, the insurance of the tourist will be demanded to be created. In order to promote China`s space tourism, it is recommended to take the “Astronaut Group Insurance” as an optional model to space tourists, if the tourists are customers of a governmental-owned space company. Once private involvement of providing orbital/suborbital tourism service becomes a reality, new rules are required. Getting a third party liability insurance is deemed as an indispensable precondition for an applicant to get a launch permission. Domestic space laws will include provisions for the third party liability insurance. China`s “Interim Measures” of 2002 realizes the importance of third party liability insurance and requires the permit holder to get it before entering the launching site. This regulation is different from the practices of other states. Concerning that China is the sponsor of APSCO, for the purpose of promoting commercial space cooperation, a harmonized approach to domestic law is recommended to be found.provisions for the third party liability insurance. China`s “Interim Measures” of 2002 realizes the importance of third party liability insurance and requires the permit holder to get it before entering the launching site. This regulation is different from the practices of other states. Concerning that China is the sponsor of APSCO, for the purpose of promoting commercial space cooperation, a harmonized approach to domestic law is recommended to be found.

DEM-CFD Analysis of Fluid Flow in Packed Bed Under the Small Column-to-Particle-Diameter Ratios

Dang Mingyan,Wang Fuxing,Jia Xinyu 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.3

In this study, a novel three-dimensional DEM-CFD numerical method was used to simulate the void fraction, pressure drop, velocity, and local fl ow in the packed bed under the small column-to-particle-diameter ( D / d ) ratios. The pseudo-continuum model method is used in the interior of particles, and for the simulation of the fl uid outside the particles, the models are established based on DEM to avoid the wall eff ect. The simulation results of void fraction and pressure drop show that the void fractions generated by the DEM method are consistent with the ones calculated from the empirical correlations; and the empirical correlations used for pressure drop in this work are basically consistent with the results of the pressure drop predicted by DEM-CFD method. The simulation results of velocity and local fl ow show that velocity distribution is related to the void fraction distribution; the radial velocity distribution depends mainly on the structure of the packed bed and is independent of the inlet velocity; and the velocity uniformities of fl uid fl ow are improved with the increasing of D / d ratio.

해외 직접 판매 사이트의 품질이 고객 충성도에 미치는 영향요인에 관한 연구

류밍옌(Mingyan Liu),성행남(Haengnam Sung),정연수(Yeonsu Jeong),정대율(Dae-Yul Jeong) 한국인터넷전자상거래학회 2016 인터넷전자상거래연구 Vol.16 No.1

The boom of oversea direct purchasing, especially in China and Asian developing countries, give us new challenge about global e-Commerce practice and consumer’s behavior research. Customers who purchase from the other country shopping mall are worry about their buying decision and delivery services. They need more information about purchasing products and want more secure transaction in the paying and delivery process. They are more sensitive about terms and conditions of business. They require high service quality to the oversees e-Commerce site. To increase the shopping mall loyalty, the oversees direct merchandising site must increase their trust as well as information system services. We assumed that the site loyalty of customer will be affected by the site trust and information service quality. The assumptions about influence factors of site trust and loyalty in the oversees direct purchasing give us a research model which was built on the basis of DeLone and McLean’s Revised Information Success Model. In the model, especially, we are interest in the role of site trust as mediating variable in the research model. To verify the validity and fitness of the model, we conducted factor analysis for the measurement variables and regression analysis with mediating variable. The model fitness was good enough. The results of regression analysis showed that all the three website quality factors(information quality, system quality, service quality) affected on the customers’ site trust, and subsequently on the site loyalty. We could prove the mediating role of site trust in the model. In addition, we analyzed the moderating effects of customer’s gender and risk taking tendency. We could not find any enough evidences about the moderating effects of two variable, but fond some different effects between site quality factors and trust in the 2×2 group analysis. We could find some import practical implications from the analysis. He who want to be a winner in the oversees direct merchandising must get customer’s trust through information and service quality management. Customer segmentation strategy is good way if the customers are sensitive to risk and price.

해외직접구매 사이트의 서비스품질이 사이트 신뢰와 재구매의도에 미치는 영향

류밍옌(Mingyan Liu),정연수(Yeonsu Jeong),정대율(Dae-Yul Jeong) 한국인터넷전자상거래학회 2015 인터넷전자상거래연구 Vol.15 No.3

In recent, Global e-Commerce operators have a lot of attention to a new combined word, Hitaozu(海淘族). "Hi(海)" means "Overseas", and ‘Tao(淘)’ means ‘Choose’ in Chinese. It says Chinese consumers enjoy overseas direct purchase using Internet. Also, the boom of oversea direct purchasing is ubiquitous in the most Asian developing countries. Nevertheless, there are many problems in delivery services and information services. Most customers of oversee direct purchasing are anxious about their purchasing decision and full of worries during the delivery process. They will have high interests in service quality factors of the e-Commerce site which will affect site trust, and subsequently user satisfaction. We can assume that repurchasing intention of customer will be affected by the antecedents of trust and customer satisfaction. We could find several service quality factors of overseas direct purchase website from SERVQUAL model and Information System Success Model, such as tangibles, assurance, empathy, and responsiveness. Especially, we are interest in the role of site trust as mediating variable in the research model. To verify the validity and fitness of structural model, we conducted second order factor analysis for the services quality factors and path analysis for the structural model. The model fitness was good enough. The path analysis results show that service quality affects customers" site trust and satisfaction, but it does not affects on repurchasing intention directly. Of the four service quality factors, assurance has the highest impact on the trust, and responsiveness was the next.

Construction of PolyheterocyclicBenzopyran Librarywith Diverse Core Skeletons through Diversity-Oriented Synthesis Pathway:Part II

Zhu, Mingyan,Lim, ByungJoon,Koh, Minseob,Park, Seung Bum American ChemicalSociety 2012 ACS Combinatorial Science Vol.14 No.2

<P>As a continuation of our previous report (J. Comb. Chem. 2010, 12, 548-558), we accomplished the diversity-oriented synthesis of polyheterocyclic small-molecule library with privileged benzopyran substructure. To ensure the synthetic efficiency, we utilized the solid phase parallel platform and the fluorous-tag-based solution-phase parallel platform to construct a 284-member polyheterocyclic library with six distinct, core skeletons with an average purity of 87% on a scale of 5-10 mg. This library was designed to maximize the skeletal diversity with discrete core skeletons in three-dimensional space and the combinatorial diversity with four different benzopyranyl starting materials and various building blocks. Together with our reported benzopyranyl library, we completed the construction of polyhetererocyclic benzopyran library with 11unique scaffolds and their molecular diversity was visualized in chemical space using principle component analysis (PCA).</P>

韓國加入亞太空間合作組織的可能性: 基于法律與政策的分析

섭명암 ( Mingyan Nie ) 한국항공우주정책·법학회(구 한국항공우주법학회) 2016 한국항공우주정책·법학회지 Vol.31 No.2

亞太空間合作組織(以下簡稱亞空組織)是亞洲地區唯一一個政府間空間合作國際組織。自成立以來至今,八個國家簽署了“亞空組織公約”幷成爲成員國。作爲亞洲重要空間國家之一,韓國在亞空組織籌備階段曾積極參與各項工作,且主辦了一屆籌備會議。但自2005年“亞空組織公約”開放簽署至今,韓國尙未簽署公約成爲成員國。 空間活動商業化與私營化的快速發展及亞洲空間商業市場規模的迅速擴大爲亞洲國家在相關領域的空間合作創造了机會。亞洲國家(例如韓國)參與到已有的亞洲空間合作組織(例如亞空組織)開展合作,是一個合适的選擇。卽便開展實質性的空間合作仍是一個不小的挑戰,在起步階段,亞洲國家可以考慮共同開展應對區域公共性事務的空間項目。 由于亞空組織借鑒了歐空局的成功經驗,所以其公約中規定的諸多法律措施可以較好的保障不同成員國間的利益分配。擧例而言,公約規定的“投資返還”原則保障了成員國投資到相應項目中的資金按照比例予以返還。此外,公約對于“基本活動”和“任擇活動”的區分賦予了成員國選擇參加合作項目的自由。而在決議程序方面,公約采用的“全體一致”的方式有利于保障成員國的利益。 但是,阻碍韓國加入亞空組織的政治因素同樣无法忽略。近期韓國宣布在其境內部署“薩德”導彈防御系統導致了中韓之間的緊張關系,客觀上影響中韓之間的空間合作。而中國沒有加入“導彈及其技術控制机制”這一事實則是美國長期以來阻碍韓國與中國開展空間合作活動的一個重要理由。 盡管短期之內无法徹底克服政治因素的阻碍作用,但仍舊可以采取法律措施減少政治因素的影響爲韓國及其他亞洲國家加入亞空組織創造條件。具體而言,亞空組織應制定執行“投資返還”原則的具體法律規范保障項目參與國投資的公平返還。此外,亞空組織還應通過分享衛星數据的方式爲區域公共事務做出貢獻。 亞空組織還可以采取如下法律措施直接減少政治因素的影響,卽:(1)明確東道國(卽:中國)的權利和責任,將東道國的責任確立爲提供協調及輔助服務。以此減少其他成員國對中國以東道國的身分控制亞空組織活動的擔憂。(2)詳細闡明組織合作的目的爲“非軍事目的”以降低參與國及其他國家的政治考量。 空間合作是未來亞洲空間活動發展的一個趨勢,如果韓國能勾加入亞空組織,則將爲建立一個完善的區域空間合作?架奠定基礎。 Asia-Pacific Space Cooperation Organization (APSCO) is the only inter-governmental space cooperation organization in Asia. Since its establishment to date, eight countries have signed the convention and become member states. South Korea participated actively in the preparatory phase of creating the organization, and one conference organized by AP-MCSTA which is the predecessor of APSCO was held in South Korea. However, after the APSCO Convention was opened for signature in 2005 to date, South Korea does not ratify the Convention and become a member. The rapid development of space commercialization and privatization, as well as the fastest growing commercial space market in Asia, provides opportunities for Asian countries to cooperate with each other in relevant space fields. And to participate in the existing cooperation framework (e.g., the APSCO) by the Asian space countries (e.g., South Korea) could be a proper choice. Even if the essential cooperation in particular space fields is challenging, joint space programs among different Asian countries for dealing with the common events can be initiated at the first steps. Since APSCO has learned the successful legal arrangements from ESA, the legal measures established by its Convention are believed to be qualified to ensure the achievement of benefits of different member states. For example, the regulation of the “fair return” principle confirms that the return of interests from the relevant programs is in proportion to the member`s investment in the programs. Moreover, the distinguish of basic and optional activities intends to authorize the freedom of the members to choose programs to participate. And for the voting procedure, the acceptance of the “consensus” by the Council is in favor of protecting the member`s interest when making decisions. However, political factors that are potential to block the participation of South Korea in APSCO are difficult to be ignored. A recent event is an announcement of deploying THAAD by South Korea, which causes tension between South Korea and China. The cooperation between these two states in space activities will be influenced. A long-standing barrier is that China acts as a non-member of the main international export control mechanism, i.e., the MTCR. The U.S takes this fact as the main reason to prevent South Korea to cooperate with China in developing space programs. Although the political factors that will block the participation of South Korea in APSCO are not easy to removed shortly, legal measures can be taken to reduce the political influence. More specifically, APSCO is recommended to ensure the achievement of commercial interests of different cooperation programs by regulating precisely the implementation of the “fair return” principle. Furthermore, APSCO is also suggested to contribute to managing the common regional events by sharing satellite data. And it is anticipated that these measures can effectively response the requirements of the rapid development of space commercialization and the increasing common needs of Asia, thereby to provide a platform for the further cooperation. In addition, in order to directly reduce the political influence, two legal measures are necessary to be taken: Firstly, to clarify the rights and responsibilities of the host state (i.e., China) as providing assistance, coordination and services to the management of the Organization to release the worries of the other member states that the host state will control the Organization`s activities. And secondly, to illustrate that the cooperation in APSCO is for the non-military purpose (a narrow sense of “peaceful purpose”) to reduce the political concerns. Regional cooperation in Asia regarding space affairs is considered to be a general trend in the future, so if the participation of South Korea in APSCO can be finally proved to be feasible, there will be an opportunity to discuss the creation of a comprehensive institutionalized framework for space cooperation in Asia.