Semiconductor Science and Information Devices最新文献

Cooperative Relaying in a Three User Downlink NOMA System Using Dynamic Power Allocation 使用动态功率分配的三用户下行 NOMA 系统中的合作中继

Semiconductor Science and Information Devices Pub Date : 2023-11-21 DOI: 10.30564/ssid.v5i1.6028

Mwewa Mabumba, Simon Tembo, Lukumba Phiri

{"title":"Cooperative Relaying in a Three User Downlink NOMA System Using Dynamic Power Allocation","authors":"Mwewa Mabumba, Simon Tembo, Lukumba Phiri","doi":"10.30564/ssid.v5i1.6028","DOIUrl":"https://doi.org/10.30564/ssid.v5i1.6028","url":null,"abstract":"Non-orthogonal multiple access (NOMA) represents the latest addition to the array of multiple access techniques, enabling simultaneous servicing of multiple users within a singular resource block in terms of time, frequency, and code. A typical NOMA configuration comprises a base station along with proximate and distant users. The proximity users experience more favorable channel conditions in contrast to distant users, resulting in a compromised performance for the latter due to the less favorable channel conditions. When cooperative communication is integrated with NOMA, the overall system performance, including spectral efficiency and capacity, is further elevated. This study introduces a cooperative NOMA setup in the downlink, involving three users, and employs dynamic power allocation (DPA). Within this framework, User 2 acts as a relay, functioning under the decode-and-forward protocol, forwarding signals to both User 1 and User 3. This arrangement aims to bolster the performance of the user positioned farthest from the base station, who is adversely affected by weaker channel conditions. Theoretical and simulation outcomes reveal enhancements within the system’s performance.","PeriodicalId":315789,"journal":{"name":"Semiconductor Science and Information Devices","volume":"63 3-4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252543","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

Minus Infinity Plus Infinity 负无穷加上正无穷

Semiconductor Science and Information Devices Pub Date : 2023-04-25 DOI: 10.30564/ssid.v5i1.5644

Kasturi Vasudevan

引用次数: 0

Air Pollution Monitoring System Using Micro Controller Atmega 32A and MQ135 Gas Sensor at Chandragiri Municipality of Kathmandu City 采用微控制器atmega32a和MQ135气体传感器的空气污染监测系统在加德满都市Chandragiri市

Semiconductor Science and Information Devices Pub Date : 2022-10-09 DOI: 10.30564/ssid.v4i2.4884

R. Shrestha, M. Maharjan, Mahesh Sharma

{"title":"Air Pollution Monitoring System Using Micro Controller Atmega 32A and MQ135 Gas Sensor at Chandragiri Municipality of Kathmandu City","authors":"R. Shrestha, M. Maharjan, Mahesh Sharma","doi":"10.30564/ssid.v4i2.4884","DOIUrl":"https://doi.org/10.30564/ssid.v4i2.4884","url":null,"abstract":"Air is one of the essential elements of human’s surroundings. The earth’s atmosphere is full of air which contains gases such as Nitrogen, Oxygen, Carbon Monoxide and traces of some rare elements. But quality of the air has been degrading for some decades due to various activities conducted by the human beings that directly or indirectly affect the atmosphere leading to the air pollution. There are different techniques to measure air quality.However, with the evolution of time the expensive and less efficient analog devices have been replaced by more efficient and less expensive electronics device. In this research, MQ135 sensor is used to measure air quality of a particular location. I2C display is used to monitor the data. Indeed, with the increasing in number of vehicles, unplanned urbanization and rapid population growth, air pollution has considerably increased in the last decades in various areas of Kathmandu. Thus, this project ‘Air Pollution Monitoring System’ was focused on collection of the data specific location of Chandragiri municipality of Kathmandu city. In conclusion,analysis of the data is done with the help of origin software which shows that the Arduino device in this device works perfectly for measuring the air pollution. Air quality of the selected area is found to be less than 500 PPM which concludes that the air quality of this area is normal.","PeriodicalId":315789,"journal":{"name":"Semiconductor Science and Information Devices","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131313254","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

Electronic Structure of CdS Nanoparticles and CdSe/CdS Nanosystems CdS纳米粒子和CdSe/CdS纳米体系的电子结构

Semiconductor Science and Information Devices Pub Date : 2022-08-12 DOI: 10.30564/ssid.v4i2.4708

V. Zavodinsky, O. Gorkusha, A. Kuz’menko

引用次数: 0

Experimentation on Optimal Configuration and Size of Thin Cylinders in Natural Convection 自然对流条件下薄圆柱的优化配置与尺寸试验

Semiconductor Science and Information Devices Pub Date : 2022-08-04 DOI: 10.30564/ssid.v4i2.4720

A. Riaz, A. Ibrahim, M. Bashir, Masroor Asghar, Muhammad Abdullah, Ajmal Shah

{"title":"Experimentation on Optimal Configuration and Size of Thin Cylinders in Natural Convection","authors":"A. Riaz, A. Ibrahim, M. Bashir, Masroor Asghar, Muhammad Abdullah, Ajmal Shah","doi":"10.30564/ssid.v4i2.4720","DOIUrl":"https://doi.org/10.30564/ssid.v4i2.4720","url":null,"abstract":"In this paper, an experimental study of laminar, steady state natural convection heat transfer from heated thin cylinders in an infinite air medium has been reported. Two electrically heated cylinders having the same slenderness ratio (L/D) i.e. 6.1 but different diameters i.e. 3.8 cm and 5.08 cm were used. 105 experiments were carried out to study the effect of diameter and inclination angle of thin cylinder on natural convection heat transfer. After mandatory corrections of radiation and endcap heat losses, convective heat transfer results were presented in the form of local and average dimensionless numbers. For vertical configuration of thin cylinder, Nusselt number was varied from 52.99 to 95.10 corresponding to 1.28×108≤Ra*L≤1.08×1010. While for horizontal configuration,Nusselt number was varied from 10.74 to 17.78 corresponding to 9.42×104≤Ra*D≤8.17×106. Results were compared with the published data and found satisfactory as the maximum percentage difference was only 3.09%. The essence of research is that the heat transfer coefficient increases with decrease in diameter and increase in inclination angle. Smoke flow visualization was done to capture patterns of fluid flow. Finally, comparison was made to quantify increase in Nusselt number from slender cylinder as compared to the flat plate.","PeriodicalId":315789,"journal":{"name":"Semiconductor Science and Information Devices","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127820449","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

Convection Heat Transfer from Heated Thin Cylinders Inside a Ventilated Enclosure 在通风的外壳内加热薄圆筒的对流传热

Semiconductor Science and Information Devices Pub Date : 2022-07-15 DOI: 10.30564/ssid.v4i2.4719

A. Riaz, A. Ibrahim, M. Bashir, Muhammad Abdullah, Ajmal Shah, A. Quddus

{"title":"Convection Heat Transfer from Heated Thin Cylinders Inside a Ventilated Enclosure","authors":"A. Riaz, A. Ibrahim, M. Bashir, Muhammad Abdullah, Ajmal Shah, A. Quddus","doi":"10.30564/ssid.v4i2.4719","DOIUrl":"https://doi.org/10.30564/ssid.v4i2.4719","url":null,"abstract":"Experimental study was conducted to determine the effect of velocity of axial fan, outlet vent height, position, area, and aspect ratio (h/w) of ventilated enclosure on convection heat transfer. Rectangular wooden ventilated enclosure having top and front transparent wall was made up of Perspex for visualization, and internal physical dimensions of box were 200 mm × 200 mm × 400 mm. Inlet vent was at bottom while outlet vents were at the side and top wall. Electrically heated cylindrical heat source having 6.1 slenderness ratio was fabricated and hanged at the centre of the enclosure. To calculate heat transfer rates, thermocouples were attached to the inner surface of heat source with silica gel. Heat source was operated at constant heat flux in order to quantify the effect of velocity of air on heat transfer. It was observed that average Nusselt number was increased from 68 to 216 by changing velocity from 0 to 3.34 m/s at constant modified Grashof number i.e. 5.67E+09. While variation in outlet height at the front wall did not affect heat transfer in forced convection region. However, Nusselt number decreased to 5% by changing the outlet position from top to the front wall or by 50% reduction in outlet area during forced convection. Mean rise in temperature of enclosure increased from 8.19 K to 9.40 K by increasing aspect ratio of enclosure from 1.5 to 2 by operating heat source at constant heat flux i.e. 541.20 w/m2.","PeriodicalId":315789,"journal":{"name":"Semiconductor Science and Information Devices","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123057412","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

Signal and Power Integrity Challenges for High Density System-on-Package 高密度系统级封装的信号和功率完整性挑战

Semiconductor Science and Information Devices Pub Date : 2022-06-13 DOI: 10.30564/ssid.v4i2.4475

Nathan Totorica, Feng Li

引用次数: 1

Apache Hadoop Architecture, Applications, and Hadoop Distributed File System Apache Hadoop架构、应用和Hadoop分布式文件系统

Semiconductor Science and Information Devices Pub Date : 2022-05-18 DOI: 10.30564/ssid.v4i1.4619

Pratit Raj Giri, Gajendra Sharma

引用次数: 1

Challenges and Opportunities for Privacy Computing 隐私计算的挑战与机遇

Semiconductor Science and Information Devices Pub Date : 2022-05-17 DOI: 10.30564/ssid.v4i1.4659

Jianhong Zhang, Chenghe Dong

引用次数: 0

Flip Chip Die-to-Wafer Bonding Review: Gaps to High Volume Manufacturing 倒装晶圆对晶圆键合回顾:与大批量生产的差距

Semiconductor Science and Information Devices Pub Date : 2022-04-07 DOI: 10.30564/ssid.v4i1.4474

Mario Di Cino, Feng Li

引用次数: 0