Design of Solar Concentrating and Redirecting Cooker “Solcr Cook”: An Innovative and Novel Thermal Hybrid Indoor Solar Cooking System

JEHANGIR AHMAD DAR 창의융합 디자인연구소 2021 창의융합연구 Vol.1 No.1

Innovative designs are sought in solar cooking systems to make the system more user friendly, highly efficient and cost effective. In seek of innovative designs this paper describes the conceptual design of novel and Innovative Thermally Hybrid Indoor Solar cooking system. In the system, by using a parabolic optical concentrator mounted on the top of structure/building the solar light is concentrated and focused to Focal reflecting element which re-directs it to the pair of Fresnel lens for converging the beam to transmit it for the larger distances. The Solar Redirector at the ground end of the system redirects the beam and transmits it to the core of the Innovative Thermal Hybrid Cooker (ITHC) using a novel approach of inbuilt ellipsoid shaped cavity adjusted with cone shaped reflective element inside the ITHC; where the solar energy gets scattered and reserved in the form of latent heat energy using Erythritol as a Phase Changing medium for late night cooking. The description of the different elements of the system is pointed out and an end-to-end optical energy efficiency analysis is performed. On estimation the system attains 83.2% of end-to-end optical efficiency, making the system novel in transmitting the solar energy directly to the core of building for cooking purposes. Using the solar radiant energy data collected by Indian Meteorological Department, Govt of India, the total transmitted diffused and global solar radiation for Jaipur city have been calculated paving the way for the exergy analysis, and further research and development of the system. The system possesses the potential to be adopted worldwide especially in Tropical regions of the globe.

Space Based Optical Transmission of Solar Energy: A New Approach to Beam-Down Solar Energy from Space for Terrestrial Use

JEHANGIR AHMAD DAR 창의융합 디자인연구소 2022 창의융합연구 Vol.2 No.1

A new architecture to beam down solar light and distribute it to different regions for the terrestrial use on the host heavenly body is presented. The architecture consist Solar Concentration and Transmission Sub-system placed in geostationary orbit to concentrate the solar light using individually pointable thin optical elements, then using Secondary Solar Reflector to deflect the produced strong intense beam to the Solar Transmission Sub-system that consists the two parallel thin Fresnel lens. The Solar Transmission Sub-system, after producing the strong convergent beam beams down it to the receiver located at the host body. The receiver is again a Fresnel lens that produces the parallel beam and transmits it to the Beam Splitter which splits the beam to a number of narrow beams and with the help of Beam Transmission and Diffuser System directs to different regions and gets diffused for the terrestrial use. A detailed mass budget of the space-oriented part Solar Concentration and Transmission Sub-system is defined. The description of the different elements of the architecture is pointed out and an end-to-end efficiency analysis is performed. 본고에서는 태양열을 빔(beam)으로 만들어 위에서부터 지상으로 쏘아 모 천체 상 서로 다른 지역의 지상에서 이용하는 새로운 설계가 제시된다. 본 시스템은 크게 태양열 집광(Solar Concentration) 시스템과 태양열 전송 하위 시스템 (Transmission Sub-system)으로 이루어져 있는데, 집광 시스템은 정지 궤도 상에 위치하였으며 개별적인 얇은 광학 요소를 이용하여 빛을 집광시키며, 이렇게 생성된 강력한 빔은 2 차적 태양열 반사기(Secondary Solar Reflector)를 통해 2 개의 평행하는 프레넬(Fresnel) 렌즈로 구성된 태양열 전송 하위 시스템으로 반사된다. 태양열 전송 하위 시스템은 강력한 융합 빔을 만든 후 모 천체 상에 위치한 수신기로 이를 전달한다. 수신기 또한 프레넬 렌즈이며 평행 빔을 생성해 빔 분열기(Beam Splitter)로 전송하는데, 분열기에서는 빔 전송 및 분산 시스템(Beam Transmission and Diffuser System)을 통해 여러 개의 얇은 빔으로 빔을 분열하여 서로 다른 지역으로 보내 지상에서의 이용을 위해 분산한다. 본고에서는 우주 지향적인 태양열 집광 시스템과 태양열 전송 하위 시스템의 상세한 질량 버짓(mass budget)을 정의한다. 설계의 서로 다른 요소가 설명되어있으며 전체적인 효율성에 대한 분석이 이루어졌다.

Effect of Foreign Direct Investment on Economic Growth of Pakistan: The ARDL Approach

Majid Jehangir,Sunhae Lee,Sae Woon Park 사람과세계경영학회 2020 Global Business and Finance Review Vol.25 No.2

Purpose: This study investigates the effect of foreign direct investment on the economic growth of Pakistan. It also explores the role and contribution of various variables in the growth of the country’s economy. Design/methodology/approach: This study examines both the long run and the short run relationship between the variables over the period 1974 - 2018 by the Auto-Regressive Distributed Lag approach. Findings: We find that in the long run, FDI, gross fixed capital formation and labor force participation have positive effect on the economic growth, whereas military expenditures have negative effect. In the short run model, however, gross fixed capital formation was indicative of having a significantly negative relationship with the economic growth while variables such as FDI, military expenditures and labor force participation were found to have positive impact. Inflation turned out to be significant but negative in both of the models while final consumption expenditure showed insignificance in both of the models. Research limitations/implications: Notwithstanding its contribution to the literature, this study has limitations as well. Apart from those measures adopted in this research, there are also other important measures necessary for a country’s economic growth such as skilled labor, work environment, infrastructure, security, technology, and so on. Yet, due to the lack or unavailability of reliable data source, we have not included these valuables in our research. If incorporated in the analysis, these measures may provide more accurate results. Pakistan is a country where military engages in various business activities such as operating department stores, military schools, universities, and hospitals and as well as constructing roads and buildings. Thus such services and contributions of the military, if studied thoroughly, may provide better statistics regarding inward FDI and its contribution towards economic growth of the country. As a policy implication, this study suggests that the Pakistani government should focus on the necessary reforms to attract more FDI, since a low-capital country like Pakistan cannot underestimate the significance of FDI for a sustainable growth. Further researches may be conducted with a focus on the growth-investment possibilities of China Pakistan Economic Corridor. Studies can also be conducted which incorporate agricultural sectors, public and private investments, trust (between land/firm owners and labor) and the existing work/business environment in order to investigate the determinants of economic development of the country. Originality/Value: To the best of our knowledge, there is only one study by Nilofer & Qayyum (2018) that uses the ARDL model to investigate the impact of FDI on economic growth of Pakistan. While they analyzed the variables including GDP, government consumption expenditure, public investment, FDI and lending rate, our study involves military expenditure, labor force participation, final consumption expenditure, gross fixed capital formation, inflation, and FDI. Also, we investigate the role of FDI on economic growth of Pakistan for a different time period 1974 to 2018 as compared to their study over the period 1970 - 2015.

Impact of Foreign Direct Investment on the Economic Growth of Pakistan

Majid Jehangir,Faiza Imad,Sae Woon Park 한국산업경제학회 2019 한국산업경제학회 정기학술발표대회 논문집 Vol.2019 No.5

Improving ANFIS Based Model for Long-term Dam Inflow Prediction by Incorporating Monthly Rainfall Forecasts

Awan, Jehangir Ashraf,Bae, Deg-Hyo Springer-Verlag 2014 Water resources management Vol.28 No.5

Development of ANFIS-based model for prediction of droughts

Awan, Jehangir Ashraf,Bae, Deg-Hyo 한국방재학회 2015 한국방재학회 학술발표대회논문집 Vol.14 No.-

Drought prediction is of significance importance for drought disaster risk management and mitigation. The regression based statistical models and physical process based models are commonly used for drought prediction. The statistical models assume stationarity of data which limits their ability to capture highly non-linear patterns of droughts. On the other hand, reliable long-range rainfall forecast is necessary for drought prediction using physical process based models. However, the long-range rainfall prediction especially in the Asian monsoon regions is quite challenging for climate models. In this study, the use of Adaptive Neuro-Fuzzy Inference System (ANFIS) was explored to develop a model for prediction of droughts over the East Asia monsoon region (20oN–50oN,103oE–149oE) by employing Standardized Precipitation Index (SPI) as a drought index. Most of the drought studies in the East Asia have been focused on basin or country scale. In this study, we identified homogeneous rainfall zones in the East Asia monsoon region using cluster analysis methods and analyzed the impact of global Sea Surface Temperature Anomalies (SSTA) on drought in each zone. The ANFIS-based model was developed and evaluated with different configurations to identify optimal model architecture and suitable predictor variables for drought prediction. The performance of the proposed model was assessed by comparison of observed and predicted values of the drought index using different statistical measures.

Phosphorus Mass Balance and Internal Load in an Impacted Subtropical Isolated Wetland

Bhadha, Jehangir H.,Jawitz, James W.,Min, Joong-Hyuk Springer-Verlag 2011 Water, Air and Soil Pollution Vol.218 No.1

Identification and trend analysis of homogeneous rainfall zones over the East Asia monsoon region

Awan, Jehangir Ashraf,Bae, Deg‐,Hyo,Kim, Kyung‐,Joong John Wiley Sons, Ltd 2015 International journal of climatology Vol.35 No.7

<P><B>ABSTRACT</B></P><P>Rainfall is a complex phenomenon with high spatiotemporal variability. Identification of homogeneous rainfall zones to better analyse the rainfall intensity and extent is of vital significance for water resources management and mitigation of potential hazards from extreme events, i.e. droughts and floods. Appropriate zoning of homogeneous rainfall regions may give better understanding of rainfall patterns by resolving small scale variations. Although homogeneous rainfall zones have been established at country scale based on climatological mean behaviour, there has been little attempt to identify zones over broader scale with consistently homogeneous rainfall variability. This study employed K‐means and Hierarchical clustering methods to establish homogeneous rainfall zones in the East Asia monsoon region (20°N–50°N, 103°E–149°E) using 30 years (1978–2007) monthly rainfall data at 0.5° grid resolution. Various cluster validation indices were used to assess the optimal number of homogeneous rainfall zones. The comparison of K‐means and Hierarchical clustering showed that although both methods were able to define the homogeneous rainfall zones well with spatial contiguity, the K‐means clustering outperformed the Hierarchical clustering in identifying more distinct zones with diverse rainfall characteristics. Mann‐Kendall and linear regression tests were used for seasonal and annual rainfall trend analysis in the homogeneous rainfall zones. The study revealed that the region experiences distinct rainfall regimes over different zones. Furthermore, significant increasing and decreasing trends were observed over different zones with strong seasonal variation that indicate the aggravated stress of climate induced disasters, i.e. droughts and floods over the East Asia monsoon region.</P>

Features and interdecadal variability of droughts in the homogeneous rainfall zones over the East Asian monsoon region

Awan, Jehangir Ashraf,Bae, Deg‐,Hyo John Wiley Sons, Ltd 2016 International journal of climatology Vol.36 No.4

<P><B>ABSTRACT</B></P><P>Features and interdecadal variability of droughts were assessed over the East Asian monsoon region (20°–50°N, 103°–149°E) using the standardized precipitation index (SPI) and the gridded rainfall data set (1978–2007) at 0.5° resolution. To assess the spatial and temporal patterns of droughts, seven homogeneous rainfall zones that exhibit unique rainfall regimes and long‐term variability over the region were used. The statistical analysis method known as the theory of runs was used to identify and characterize drought events. A run was defined as a portion of SPI drought series in which all values were below the selected threshold level. Run‐length and run‐sum were used to define the drought duration and drought severity, respectively. The study revealed unique drying and wetting patterns for different zones in the region. Interdecadal analysis of droughts over the past three decades revealed a significant increase in drought duration and severity in the low rainfall zones, whereas a significant decrease appeared in the high rainfall zones. In particular, the duration and severity dwindled to zero with no major drought event over the eastern and the East Sea coastal region of Japan during the last decade (1998–2007). These patterns pose serious threats of increasing droughts in the low rainfall zones and flooding in the high rainfall zones. The spectral analysis, using the Fast Fourier Transform, was performed to identify the cyclic patterns of SPI time series in each zone, which revealed dominant cycles of 15, 7.5, and 3.4 years in the different zones. These results suggest the possible influence of interdecadal Pacific Oscillations and North Atlantic Oscillations on droughts in the region, although these relations remain a challenging task.</P>

A Novel Approach for Blind Estimation of Reverberation Time using Gamma Distribution Model

Hamza, Amad,Jan, Tariqullah,Jehangir, Asiya,Shah, Waqar,Zafar, Haseeb,Asif, M. The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.2

In this paper we proposed an unsupervised algorithm to estimate the reverberation time (RT) directly from the reverberant speech signal. For estimation process we use maximum likelihood estimation (MLE) which is a very well-known and state of the art method for estimation in the field of signal processing. All existing RT estimation methods are based on the decay rate distribution. The decay rate can be obtained either from the energy envelop decay curve analysis of noise source when it is switch off or from decay curve of impulse response of an enclosure. The analysis of a pre-existing method of reverberation time estimation is the foundation of the proposed method. In one of the state of the art method, the reverberation decay is modeled as a Laplacian distribution. In this paper, the proposed method models the reverberation decay as a Gamma distribution along with the unification of an effective technique for spotting free decay in reverberant speech. Maximum likelihood estimation technique is then used to estimate the RT from the free decays. The method was motivated by our observation that the RT of a reverberant signal when falls in specific range, then the decay rate of the signal follows Gamma distribution. Experiments are carried out on different reverberant speech signal to measure the accuracy of the suggested method. The experimental results reveal that the proposed method performs better and the accuracy is high in comparison to the state of the art method.