• ETRI Journal
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• 제38권6호
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• pp.1172-1178
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• 2016

The atmospheric meteorology parameters of the earth, such as temperature, pressure, and humidity, strongly influence the propagation of signals in Global Navigation Satellite Systems (GNSSs). The propagation delays associated with GNSS signals can be modeled and explained based on the atmospheric temperature, pressure, and humidity, as well as the locations of the satellites and receivers. In this paper, we propose an optimized and simplified low cost GNSS base weather station that can be used to provide a global estimate of the integrated water vapor value. Our algorithm can be used to measure the zenith tropospheric delay based on the measured propagation delays in the received signals. We also present the results of the data measurements performed at our station located in the Tlemcen region of Algeria.

• Computers and Concrete
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• 제25권4호
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• pp.343-354
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• 2020

In this paper, vibration characteristics of chiral double-walled carbon nanotubes entrenched on Kelvin's model. The Eringen's nonlocal elastic equations are being combined with Kelvin's theory to observe small scale response. A nonlocal model has been formulated to explore the frequency spectrum of chiral double-walled CNTs along with diversity of indices and nonlocal parameter. Wave propagation is proposed technique to establish field equations of model subjected to four distinct end supports. The significance of scale effect in relevance of length-to-diameter and thickness- to- radius ratios are discussed and displayed in detail.

• Computers and Concrete
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• 제25권2호
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• pp.133-144
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• 2020

This paper aims to study vibration characteristics of chiral and zigzag double-walled carbon nanotubes entrenched on Donnell shell model. The Eringen's nonlocal elastic equations are being combined with Donnell shell theory to observe small scale response. Wave propagation is proposed technique to establish field equations of model subjected to four distinct end supports. A nonlocal model has been formulated to explore the frequency spectrum of both chiral and zigzag double-walled CNTs along with diversity of indices and nonlocal parameter. The significance of scale effect in relevance of length-to-diameter and thickness- to- radius ratios are discussed and displayed in detail. The numerical solution based on this nonlocal Donnell shell model can be further used to predict other frequency phenomena of double-walled and multi-walled CNTs.

• Advances in materials Research
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• 제11권3호
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• pp.211-224
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• 2022

The shrinkage and the mechanical properties of polypropylene hybrid fiber reinforced mortar PHFRM were investigated in this study. Mortars were prepared with limestone crushing sand, Portland cement and polypropylene hybrid fibers PHF. Two types of virgin fibers, having the same length (30 mm) were used for reinforcing test mortars, fibers in diameter of 0.45 mm, used by PLAST BROS factory of Bordj Bou Arreridj (Algeria) for the fabrication of brooms (for household cleaning) and fibers in diameter of 0.25 mm, available on the market, having multiple applications. In this investigation, it was aimed to study the total and autogenous shrinkage, the flexural and compressive strength of mortars based on hybrid fibers. As a result, PHF have negatively affected the mortar workability. However, shrinkage risk was reduced and coarser fibers (PF45) were most effective for reducing shrinkage risk. The mechanical performances and the ductility of PHFRM were also enhanced.

• 대한공간정보학회지
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• 제23권1호
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• pp.89-99
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• 2015

최근 국내 도시개발 업계의 제3세계 개발도상국가 도시계획용역 및 도시개발사업 참여기회가 크게 증대하는 추세이며, 이는 국내 개발여건 침체국면 타개를 위한 유효 대안으로서 크게 기대되고 있다. 그러나 대부분 개발타당성 검토과정에서부터 당면하는 애로사항 중 하나가 당해 개발도상국의 기초통계자료 및 공간정보 부재라 하겠다. 국가지리정보나 수치지도 등의 구축은 개도국 차원에서 단기간 내 완성하기는 어렵기 때문에 따라서 개발참여를 위한 기초조사, 분석 및 기본계획 단계에서부터 큰 리스크를 감수할 수밖에 없는 것이 현실이다. 본 연구는 이러한 맥락에서 아프리카 북단에 위치한 알제리의 밥 에주아흐 지역을 대상으로 대체적 방법을 통해 지역현황 분석 및 기본계획 작성에 필요한 개략적인 지역 베이스맵 준비과정을 시연해 봄으로써 자료한계 문제를 극복하기 위한 대안을 제시해 보고자 한다. 이를 위해, 온라인에서 획득 가능한 맵타일로부터 모자이크 맵을 구축하고 위성사진을 기반으로 건축물 특성자료를 구축하며, 수치입력 방법으로 도로 네트워크를 구축하는 등 일련의 기술적 과정을 예시해 보고자 한다. 또한 이렇게 구축된 베이스맵에 근거해 기초적 마스터플랜 개념도를 예시해 봄으로써 그 응용 가능성을 예시해 보고자 한다.

• 한국지역지리학회지
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• 제22권4호
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• pp.745-760
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• 2016

지명은 특정 물리적 공간을 나타낼 뿐만 아니라, 사회적이고 정치적인 권력 관계를 표상하고 있다. 특히 동해는 우리나라 영역을 나타내는 대표적인 지명일 뿐만 아니라, 해외에서는 일본해와 경쟁관계에 있는 지명이다. 우리나라는 국제사회에서 동해 지명 확산을 위해 다방면으로 노력하고 있으며, 점차 그 권력을 확대하고 있다. 본 연구는 프랑스를 제외한 주요 불어권 국가의 방송사 신문사의 실제 기사와 방송 내용 분석을 통해 동해 관련 표기 명칭의 현 상황을 도출하고, 프랑스에서 생산된 표기 명칭이 불어권 각 국가로 확산되는 과정과 영향력을 지명의 권력 관계 측면에서 밝히고자 하였다. 불어권 국가 중 북아프리카의 알제리, 서유럽의 벨기에, 룩셈부르크, 캐나다 퀘벡을 주요 연구 지역으로 선정하였다. 연구 결과, 북아프리카 알제리와 룩셈부르크 언론 매체는 동해 표기에 비호의적인 경향을 보인 반면, 벨기에와 퀘벡은 비교적 호의적이었다. 대체로 불어권 국가들은 프랑스의 AFP 통신으로부터 보도 자료를 제공 받고 있었는데, 동일한 기사라 하더라도 각 국가나 언론사에 따라 일본해 단독 표기를 고수하려는 매체가 있기도 하고, 경우에 따라 동해를 병기 표기하려는 의지를 보이는 곳도 있었다. 이를 통해 지명 확산과 전파의 사회적 정치적 이해 관계와 지명에서 나타난 권력관계, 대중적 지정학의 중요성을 강조하고자 하였다.

• 공업화학
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• 제33권6호
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• pp.563-573
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• 2022

This work aimed to develop a new equation for turbidity (Turb) simulation and prediction using statistical methods based on principal component analysis (PCA) and multiple linear regression (MLR). For this purpose, water samples were collected monthly over a five year period from Cheurfa dam, an important reservoir in Northwestern Algeria, and analyzed for 12 parameters, including temperature (T°), pH, electrical conductivity (EC), turbidity (Turb), dissolved oxygen (DO), ammonium (NH₄⁺), nitrate (NO₃^-), nitrite (NO₂^-), phosphate (PO₄^3-), total suspended solids (TSS), biochemical oxygen demand (BOD₅) and chemical oxygen demand (COD). The results revealed a strong mineralization of the water and low dissolved oxygen (DO) content during the summer period. High levels of TSS and Turb were recorded during rainy periods. In addition, water was charged with phosphate (PO₄^3-) in the whole period of study. The PCA results revealed ten factors, three of which were significant (eigenvalues >1) and explained 75.5% of the total variance. The F1 and F2 factors explained 36.5% and 26.7% of the total variance, respectively and indicated anthropogenic pollution of domestic agricultural and industrial origin. The MLR turbidity simulation model exhibited a high coefficient of determination (R² = 92.20%), indicating that 92.20% of the data variability can be explained by the model. TSS, DO, EC, NO₃^-, NO₂^-, and COD were the most significant contributing parameters (p values << 0.05) in turbidity prediction. The present study can help with decision-making on the management and monitoring of the water quality of the dam, which is the primary source of drinking water in this region.

• Structural Engineering and Mechanics
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• 제47권4호
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• pp.471-493
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• 2013

This paper presents a framework for seismic damage evaluation for Algerian buildings adapted from HAZUS approach (Hazard-United States). Capacity and fragility curves were adapted to fit the Algerian building typologies (Reinforced Concrete structures, Confined or Non-Confined Masonry, etc). For prediction purposes, it aims to estimate the damages and potential losses that may be generated by a given earthquake in a prone area or country. Its efficiency is validated by comparing the estimated and observed damages in Boumerd$\grave{e}$s city, in the aftermath of Boumerd$\grave{e}$s earthquake (Algeria: May $21^{st}$ 2003; $M_w$ = 6.8). For this purpose, observed damages reported for almost 3,700 buildings are compared to the theoretical predictions obtained under two distinct modelling of the seismic hazard. In one hand, the site response spectrum is built according to real accelerometric records obtained during the main shock. In the other hand, the effective Algerian seismic code response spectrum (RPA 99) in use by the time of the earthquake is considered; it required the prior fitting of Boumerd$\grave{e}$s site PGA (Peak Ground Acceleration) provided by Ambraseys' attenuation relationship.

• Geomechanics and Engineering
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• 제13권1호
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• pp.119-139
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• 2017

Static Penetration Test (CPT) and Dynamic Penetration Test (DPT) are commonly used in-situ tests in a routine geotechnical investigation. Besides their use for qualitative investigation (lithology, homogeneity and spatial variability), they are used as practical tools of geotechnical characterization (resistance to the penetration, soil rigidity) and modern foundation design as well. The paper aims at presenting the results of an extensive research work on the evaluation of the 1D primary consolidation settlement of saturated clayey soils on the basis of the CPT or DPT tests. The work is based on an analysis of the correlations between the tip resistance to penetration measured in these tests and the parameters of compressibility measured by the compressibility oedometer test, through a local geotechnical database in the northern Algeria. Such an analysis led to the proposal of two methods of calculation of the settlement, one based on the CPT test and the other one on the DPT. The comparison between the predicted settlements and those computed on the basis of the oedometer test showed a good agreement which demonstrate the possbility to use the CPT and DPT tests as reliable tools of computation of foundation settlements in clayey soils.

• Journal of Electrical Engineering and Technology
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• 제3권1호
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• pp.60-67
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• 2008

The vibrations and noise origin in electric material is due to several coupled physical phenomena. The revolving electric machine complete modeling is complex; it does not allow simple parametric machine structure studies for various operation modes. This work presents a simple electromagnetic model which makes possible the machine principal parts flow estimation from flux density. Special interest is given in determining Switched Reluctance Machine (S.R.M) radial acceleration in accordance with the current supply. Our focus will be only on the magnetic origin efforts that are dominating in the S.R.M. The efforts calculation versus the current is presented in the case of a machine with a linearized rate. These efforts are considered as a tangential force producing the torque and a radial force that generates no torque. The application is realized on a 6/4 low power S.R.M type (6 stator teeth and 4 teeth rotor). The mechanical response is substituted in a transfer function. The model takes account of the power supply of the machine, the relation between the current supply and the efforts as well as the vibratory response of the machine to these efforts. Finally, the model is validated by comparison with similar experimental results within the framework of the definite assumptions.