http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
An improved backtracking search optimization algorithm for cubic metric reduction of OFDM signals
Hojjat Emami,Abbas Ali Sharifi 한국통신학회 2020 ICT Express Vol.6 No.3
The large amplitude variations of OFDM signals generate in-band distortion and out-of-band radiation. In recent years, cubic metric (CM) has been verified as a more accurate metric to measure the amplitude variations. In this paper, the PTS technique is used to decrease the CM of OFDM signals. To overcome the search complexity of an exhaustive search based PTS technique, we introduce an improved backtracking search (IBS) optimization algorithm. Simulations are conducted to show the advantages of the proposed IBS based PTS approach compared with the conventional OFDM, and several state-of-the-art methods in terms of search complexity and CM reduction performance.
Economic Impacts of Energy Development on Domestic Economy
Hojjat, Tahereh Alavi Korea Distribution Science Association 2014 The Journal of Asian Finance, Economics and Busine Vol.1 No.1
New technologies and techniques to extract natural gas and gas liquids, as well as petroleum, from shale rock have greatly altered expectations for North America's capacity to produce energy products. As a result of innovations such as hydraulic fracturing, some government, industry, and academic observers have predicted that the United States will soon become energy self-sufficient and possibly become a net exporter of natural gas and petroleum. This paper will cover literature review and measure the potential impacts on economic growth and development. Fracking, renewable energy are just a few of the things that have reshaped the energy picture over the past 20 years, how much it will change in the next 20 years and the impacts on the economy will be discussed.
Clinical Findings and Results of Surgical Resection of Thoracolumbar Osteoid Osteoma
Hojjat Hossein Pourfeizi,Ali Tabrizi,Mohammad Reza Bazavar,Jafar Ganjpour Sales 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.2
Study Design: Descriptive, cases series study. Purpose: To evaluate clinical findings and results of treatment of patients with spinal osteoid osteoma who underwent surgery. Overview of Literature: Osteoid osteoma is a benign tumor with spinal involvement rate of about 10%. It is manifested during adolescence with symptoms such as painful scoliosis. To treat the problem, operation on the patients and excising the nidus are suggested. Methods: This descriptive study was conducted on 11 patients with spinal osteoid osteoma at our orthopedic educational center. All patients were treated through open surgery and nidus curettage. All samples were pathologically confirmed. Imaging methods (spiral computed tomography-scan) was used in preoperative planning. Scoliosis and other clinical findings were studied. Results: The study was conducted on 11 patients comprising 6 females (54.5%) and 5 males (45.5%) with the mean age of 14.6 years. Mean deviation of scoliosis resulting from spinal osteoid osteoma was 22.8 degrees. There was more scoliosis in the involvement of the lumbar vertebra. In comparison with adults, scoliosis was more severe in youths. There was one case of vertebra body involvement with manifestation of painful scoliosis. Due to lack of careful preoperative examination, the surgery was repeated for this case. No sign of recurrence was observed in patients who underwent open surgery and all scoliosis in the follow-up had improved. Conclusions: Based on our findings, surgical excision of spinal ostoeid osteoma was successful and complete recovery was achieved in spinal deformity in the course of follow-up. Scoliosis is often seen during adolescence and lumbar involvement is more severe.
On $\phi$-$n$-absorbing primary ideals of commutative rings
Hojjat Mostafanasab,Ahmad Yousefian Darani 대한수학회 2016 대한수학회지 Vol.53 No.3
All rings are commutative with $1\neq0$ and $n$ is a positive integer. Let $\phi:\mathfrak{J}(R)\rightarrow \mathfrak{J}(R)\cup\{\emptyset\}$ be a function where $\mathfrak{J}(R)$ denotes the set of all ideals of $R$. We say that a proper ideal $I$ of $R$ is {\it $\phi$-$n$-absorbing primary} if whenever $a_1,a_2,\dots,a_{n+1}\in R$ and $a_1a_2\cdots a_{n+1}\in I\backslash\phi(I)$, either $a_1a_2\cdots a_n\in I$ or the product of $a_{n+1}$ with $(n-1)$ of $a_1,\dots,a_n$ is in $\sqrt{I}$. The aim of this paper is to investigate the concept of $\phi$-$n$-absorbing primary ideals.
Determining the heat flux absorbed by satellite surfaces with temperature data
Hojjat Behrooz Khaniki,S. M. Hossein Karimian 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.6
This study aims to determine the heat flux absorbed by satellite surfaces with the use of temperature data acquired from the satellite. This process is the first step in the development of an attitude determination method, which is currently being conducted by the authors. The principles of heat flux determination and its limitations are explained. A simple heat flux sensor is proposed in this study to addresssuch limitations. With sufficient temperature data, an inverse solution of the energy equation can be used to determine the heat fluxesabsorbed by heat flux sensors. The accuracy of the method depends on the resolution of the sensors used to acquire temperature data. Theeffects of temperature sensor resolution on the accuracy of the results are discussed in this paper.
EXISTENCE OF FIXED POINTS OF SET-VALUED MAPPINGS IN b-METRIC SPACES
Hojjat Afshari,Hassen Aydi,Erdal Karap nar 영남수학회 2016 East Asian mathematical journal Vol.32 No.3
In this paper, we introduce the notion of generalized α-ψ-Geraghty multivalued mappings and investigate the existence of a xedpoint of such multivalued mappings. We present a concrete example andan application on integral equations illustrating the obtained results.
Cloud task scheduling using enhanced sunflower optimization algorithm
Hojjat Emami 한국통신학회 2022 ICT Express Vol.8 No.1
The objective of cloud task scheduling is to partition tasks on shared resources to minimize energy consumption and makespan. Recently, several meta-heuristics for task scheduling were proposed and achieved encouraging results. However, their performance is far from the ideal state and needs more improvement. This paper introduces an enhanced sunflower optimization (ESFO) algorithm for improving the performance of existing task scheduling. It finds optimal scheduling in a polynomial time. The experiments show that ESFO outperformed its counterparts. The amount of improvement in comparison with the best counterpart is 0.73% and 2.24% respectively in terms of makespan and energy consumption.