Journal of Science and Technology Issue on Information and Communications Technology最新文献_第9页

Optical Mode Cross-Connect Using Multimode Interference Mmi Based On Silicon Material 基于硅材料的多模干涉Mmi光模交叉连接

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2022-06-30 DOI: 10.31130/ud-jst.2022.160ict

Ho Duc Tam Linh, Vo Duy Phuc, Nguyễn Quang Việt, Nguyen Duc Hien, N. Hung

{"title":"Optical Mode Cross-Connect Using Multimode Interference Mmi Based On Silicon Material","authors":"Ho Duc Tam Linh, Vo Duy Phuc, Nguyễn Quang Việt, Nguyen Duc Hien, N. Hung","doi":"10.31130/ud-jst.2022.160ict","DOIUrl":"https://doi.org/10.31130/ud-jst.2022.160ict","url":null,"abstract":"An optical mode cross-connect (OMXC) between fundamental modes using multimode interference coupler MMI with high performance has been proposed in this paper. These basic modes can be transmitted in turn or at the same time toany input and be able to select arbitrary outputs. The following inputs can only select the remaining outputs, so this process will not cause bottlenecks in the circuit. In order for the signals to be flexibly switched to the outputs without conflict, the phase shifters will be used to control their lightpaths. Through the BPM-3D beam propagation method, we have shown the flexible switching process between the input and output ports of the device with insertion loss always smaller than 1.8 dB in the range of wide wavelength from 1.53 µm to 1.565 µm. Specifically, attenuation only reaches -0.5 dB at the central wavelength of 1.55 µm. In addition, the crosstalk is always in a very small range from -44 dB to -24 dB for the entire band considered above. With these advantages, it is a promising device for optical mode processing circuits in the MDM system.","PeriodicalId":262140,"journal":{"name":"Journal of Science and Technology Issue on Information and Communications Technology","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130142977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On The Optimization of Weighted Sum Rate for Mimo Broascast Channels Mimo广播信道加权和速率优化研究

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2022-06-30 DOI: 10.31130/ud-jst.2022.144

V. Nguyen-Duy-Nhat, M. T. P. Le, H. Nguyen-Le

{"title":"On The Optimization of Weighted Sum Rate for Mimo Broascast Channels","authors":"V. Nguyen-Duy-Nhat, M. T. P. Le, H. Nguyen-Le","doi":"10.31130/ud-jst.2022.144","DOIUrl":"https://doi.org/10.31130/ud-jst.2022.144","url":null,"abstract":"n this paper, we study the problem of optimizing the weighted total system rate (WSR) for a downlink broadcast communication system using multiple input-multiple output (MIMO) antenna technology, wherein a Base station (BS) transmits multiple data streams simultaneously to K multi-antenna MIMO mobile stations (MSs). Upon the power constraint, the optimal solution is to find the pre-coding matrices at the BS and the decoding matrices at the MSs. However, this type of optimization problem is usually nonlinear and non-convex, so it is relatively difficult to solve by analytical methods. To tackle the problem, we propose a novel algorithm to optimize the WSR of the system based on the Harris Hawking Optimization (HHO) algorithm using the linear least squares mean error (MMSE) filter at the MSs. Numerical results have been used to demonstrate the outperformance of the proposed algorithm, comparing with existing methods such as Block Diagonalism with Waterfilling algorithm and Particle Swarm Optimization, particularly at the low signal-to-noise (SNR) range. In the end, we may propose an adaptive method that combines the advantages of different algorithms at various SNR domains to maximize the system performance.","PeriodicalId":262140,"journal":{"name":"Journal of Science and Technology Issue on Information and Communications Technology","volume":"134 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128345745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Online news consumption about COVID-19 pandemic a snapshot from Vietnam 关于COVID-19大流行的在线新闻消费——来自越南的快照

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2022-06-30 DOI: 10.31130/ud-jst.2022.258e

TrangKhanh Tran

引用次数: 0

A study on the synthesis of MoS2/rGO and the investigation of their charge-discharge properties when used as cathode material in a rechargeable Zn-ion battery 二硫化钼/氧化石墨烯的合成及其在可充电锌离子电池正极材料中的充放电性能研究

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2022-06-30 DOI: 10.31130/ud-jst.2022.242e

Kien Nguyen-Ba Nguyen, H. Le, Anh T. Vo Vo, D. Luu

{"title":"A study on the synthesis of MoS2/rGO and the investigation of their charge-discharge properties when used as cathode material in a rechargeable Zn-ion battery","authors":"Kien Nguyen-Ba Nguyen, H. Le, Anh T. Vo Vo, D. Luu","doi":"10.31130/ud-jst.2022.242e","DOIUrl":"https://doi.org/10.31130/ud-jst.2022.242e","url":null,"abstract":"Recently, rechargeable aqueous Zn-ion batteries have attracted much attention and are potential candidates for grid storage applications because of their low cost and safety. However, to approach practical applications, suitable cathode materials must be developed. As a two-dimensional layered material, MoS2-based materials are very potential candidates. Herein, MoS2/rGO materials were synthesized by hydrothermal method and then the charge-discharge properties of the fabricated materials were investigated when they are used as cathode materials for rechargeable Zn-ion batteries. The MoS2/rGO has an expanded interlayer, which achieves a high initial capacity of about 170 mAh/g but does not have a high stability. In contrast, the MoS2-KOA has a low capacity but is very stable, even after 200 charge/discharge cycles. This study has shown the advantages and disadvantages of MoS2-based materials with expanded interlayer and suggests further work to find methods to stabilize the expanded interlayer to increase the charge/discharge stability.","PeriodicalId":262140,"journal":{"name":"Journal of Science and Technology Issue on Information and Communications Technology","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133716977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Are longer annual reports less readable? Evidence from foreign firms listed on the United States Stock Exchanges 较长的年度报告可读性较差吗?来自在美国证券交易所上市的外国公司的证据

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2022-06-30 DOI: 10.31130/ud-jst.2022.095e

Nguyen Thi Thuy Phuong, Nguyen Thanh Huong Nguyen

引用次数: 0

Investigation of pest species and population dynamics of the oriental fruit fly, Bactrocera dorsalis (Hendel, 1912), in the water apple gardens in different seasons, Caolanh city, Dongthap province 东萨省曹兰市不同季节水苹果园桔小实蝇(Bactrocera dorsalis, Hendel, 1912)害虫种类及种群动态调查

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2022-06-30 DOI: 10.31130/ud-jst.2022.040ict

Nguyen Thi Nguyen

{"title":"Investigation of pest species and population dynamics of the oriental fruit fly, Bactrocera dorsalis (Hendel, 1912), in the water apple gardens in different seasons, Caolanh city, Dongthap province","authors":"Nguyen Thi Nguyen","doi":"10.31130/ud-jst.2022.040ict","DOIUrl":"https://doi.org/10.31130/ud-jst.2022.040ict","url":null,"abstract":"Twenty-six species of insect pests belonging to thirteen families, eight orders were identified after the surveys in some gardens of the water apple (Syzygium samarangense) in Hoa An Commune of Caolanh city, Dongthap province, Southern Vietnam. Some species of the pests, e.g., Aleuroclava aucubae, Trialeurodes lauri, Trichopsocus clarus, are new recorded in Vietnam. The oriental fruit fly Bactrocera dorsalis is one of the major pest species devastating the water apple. Rainfall is a factor comprehensively influencing the population fluctuation of the oriental fruit fly. The pest population was exploded in the dry season, but reduced remarkably in the rainy season. The fruiting period from February to April was regarded as another major factor influencing the oriental fruit fly population in that area. The results provide scientific data for establishing practical management strategy for the fly under the particular geographical and climatic conditions, especially for the oriental fruit fly Bactrocera dorsalis.","PeriodicalId":262140,"journal":{"name":"Journal of Science and Technology Issue on Information and Communications Technology","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131790103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The impacts of corporate social resposibility practices on firm financial performance: Empirical evidence from Asian oil and gas industry 企业社会责任实践对企业财务绩效的影响:来自亚洲油气行业的经验证据

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2021-12-31 DOI: 10.31130/ud-jst2021-019e

N. T. Nguyen

引用次数: 0

Aralia armata roots: Extraction, isolation and molluscicidal activity against golden apple snails, Pomacea canaliculata 木耳根的提取、分离及对金苹果螺的杀螺活性研究

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2021-12-31 DOI: 10.31130/ud-jst2021-013e

N. H. Nguyen

引用次数: 0

Detecting the coral bleaching at the coral reefs of Son Tra peninsula and Cu Lao Cham Island in the South central coast region of Vietnam 在越南中南部海岸的松特拉半岛和古老占岛的珊瑚礁监测珊瑚白化情况

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2021-12-31 DOI: 10.31130/ud-jst2021-014e

D. Duong

引用次数: 0

The degradation of methylene blue by microcubes catalyst -Fe2O3 via heterogenous Fenton process 微立方体催化剂-Fe2O3在非均相Fenton法降解亚甲基蓝的研究

Journal of Science and Technology Issue on Information and Communications Technology Pub Date : 2021-12-31 DOI: 10.31130/ud-jst2021-016e

Ngo Thi My Binh Ngo

引用次数: 0