‘X’ Shape Slot based Microstrip Fractal Antenna for IEEE 802.11 WLAN

Ram Krishan,김혜진 사단법인 인문사회과학기술융합학회 2016 예술인문사회융합멀티미디어논문지 Vol.6 No.8

In this paper a novel fractal microstrip antenna is proposed for IEEE 802.11 Wireless Local Area Network (WLAN). The geometry of ‘X’ shape slots with dissimilar dimensions is used to design the proposed fractal antenna. The proposed fractal antenna is designed with FR4 Glass Epoxy material. The dielec­tric constant and thickness of antenna are er=4.4 and 1.6mm. Radiating patch size of proposed antenna is of 35.4mm x 27.82mm with feed width and length 16.4mm and 2.6mm respectively. Proposed fabricated antenna is analyzed for WLAN frequency band of 2.4GHz. Ansoft HFSS simulator software is used to obtain and validate the simulation results of proposed antenna.

Optimal Allocation of Distributed Solar Photovoltaic Generation in Electrical Distribution System under Uncertainties

Ashu Verma,Arjun Tyagi,Ram Krishan 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.4

In this paper, a new approach is proposed to select the optimal sitting and sizing of distributed solar photovoltaic generation (SPVG) in a radial electrical distribution systems (EDS) considering load/generation uncertainties. Here, distributed generations (DGs) allocation problem is modeled as optimization problem with network loss based objective function under various equality and inequality constrains in an uncertain environment. A boundary power flow is utilized to address the uncertainties in load/generation forecasts. This approach facilitates the consideration of random uncertainties in forecast having no statistical history. Uncertain solar irradiance is modeled by beta distribution function (BDF). The resulted optimization problem is solved by a new Dynamic Harmony Search Algorithm (DHSA). Dynamic band width (DBW) based DHSA is proposed to enhance the search space and dynamically adjust the exploitation near the optimal solution. Proposed approach is demonstrated for two standard IEEE radial distribution systems under different scenarios.

Optimal Allocation of Distributed Solar Photovoltaic Generation in Electrical Distribution System under Uncertainties

Verma, Ashu,Tyagi, Arjun,Krishan, Ram The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.8 No.1

In this paper, a new approach is proposed to select the optimal sitting and sizing of distributed solar photovoltaic generation (SPVG) in a radial electrical distribution systems (EDS) considering load/generation uncertainties. Here, distributed generations (DGs) allocation problem is modeled as optimization problem with network loss based objective function under various equality and inequality constrains in an uncertain environment. A boundary power flow is utilized to address the uncertainties in load/generation forecasts. This approach facilitates the consideration of random uncertainties in forecast having no statistical history. Uncertain solar irradiance is modeled by beta distribution function (BDF). The resulted optimization problem is solved by a new Dynamic Harmony Search Algorithm (DHSA). Dynamic band width (DBW) based DHSA is proposed to enhance the search space and dynamically adjust the exploitation near the optimal solution. Proposed approach is demonstrated for two standard IEEE radial distribution systems under different scenarios.

Regeneration dynamics, population structure, and forest composition in some ridge forests of the Western Himalaya, India

Om Prakash Tiwari,Yashwant Singh Rana,Ram Krishan,Chandra Mohan Sharma,Bhupendra Singh Bhandari 한국산림과학회 2018 Forest Science And Technology Vol.14 No.2

The present study aimed to analyze the regeneration dynamics, population structure, and forest composition in some ridge forests of the Western Himalaya to elucidate the impact of climate change. The highest species richness (trees, 17; saplings, 16; seedlings, 16) was recorded in mixed Rhododendron arboreum forest. The maximum tree density (737 § 25.93 trees ha¡1; mixed Quercus floribunda); sapling density (5342 § 587.54 saplings ha¡1; mixed Quercus semecarpifolia), and seedling density (71,429 § 26,632.29 seedlings ha¡1; mixed Cedrus deodara) were recorded in forests of higher altitudes. The mean basal cover values in these forests oscillated between 39.21 § 1.53 m2 ha¡1 (mixed Quercus leucotrichophora) to 87.65 § 15.45 m2 ha¡1 (mixed Abies pindrow). The highest Shannon index value (0.51 § 0.05) and species evenness (0.36 § 0.02) for trees were recorded in mixed Rhododendron arboreum forest. Some species like Betula utilis, Myrica esculenta, Ficus rumphii, Ilex dipyrena, Quercus floribunda, Litsea elongata, Symplocos paniculata, and Abies spectabilis were noticed as new recruiters (recent invaders) in new habitats, which may change the future forest composition. This study revealed that ridge forests of the Bhagirathi catchment area were in transition phase at middle altitudes. Mixed Quercus floribunda forest was observed to be the youngest regenerating forest; however, mixed Abies pindrow forest was the most mature old-growth forest.

Disturbance, Diversity, Regeneration and Composition in Temperate Forests of Western Himalaya, India

Om Prakash Tiwari,Chandra Mohan Sharma,Yashwant Singh Rana,Ram Krishan 강원대학교 산림과학연구소 2019 Journal of Forest Science Vol.35 No.1

We have investigated the impact of anthropogenic and natural disturbances on regeneration, composition and diversity in some temperate forests of Bhagirathi Catchment Area of Garhwal Himalaya. The forests were categorized on the basis of canopy cover and magnitude of disturbance into highly, moderately and least disturbed classes. The dominant tree species at lower elevation were Pinus roxburghii and Quercus leucotrichophora, while Abies pindrow, Q. semecarpifolia and Rhododenron arboreum were the dominant species at the upper elevational forests. Cythula tomentosa and Indegophera heterentha were the dominant shrub species present in all the forests. Similarly, Circium wallichii and Oxalis corniculata were the dominant herb species found in all forests (except Q. leucotrichophora forest), whereas Thalictrum foliolosum and Viola pilosa were noticed in each forest (except P. roxburghii forest). The tree density values oscillated between 400±10 trees ha-1 to 750±89.1 trees ha-1 which generally decreased from lower to higher disturbance regimes however, the total basal cover value was highest (88.1±23.6 m2 ha-1) in highly disturbed forest and lowest (25.8±2.2 m2 ha-1) in moderately disturbed forest. The shrub and herb densities were maximum in least disturbed forest, while the young regenerating individuals i.e., sapling and seedling were observed increasing from high to low disturbed forests which reflected that the forest fragmentation adversely affected the regeneration. However, A. pindrow and P. roxburghii were found invariably encroaching the habitats of R. arboreum and Q. leucotrichophora at various altitudes, respectively. The Canonical Correspondence Analysis clearly indicated that the elevation and lopping intensity have more impact on trees, while shrub and herbs were more influenced by elevation, canopy cover, light attenuation and soil erosion. Pinus roxburghii was the only species which was affected by heavy litter removal and forest fire.

Plant Diversity, Tree Regeneration, Biomass Production and Carbon Storage in Different Oak Forests on Ridge Tops of Garhwal Himalaya

Sharma, Chandra Mohan,Tiwari, Om Prakash,Rana, Yashwant Singh,Krishan, Ram,Mishra, Ashish Kumar Institute of Forest Science 2016 Journal of Forest Science Vol.32 No.4

The present study was conducted on ridge tops of moist temperate Oak forests in Garhwal Himalaya to assess the plant diversity, regeneration, biomass production and carbon assimilation in different Oak forests. For this purpose, three Oak forest types viz., (a) Quercus leucotrichophora or Banj Oak (FT1; between 1,428-2,578 m asl), (b) Quercus floribunda or Moru Oak (FT2; between 2,430-2,697 m asl) and (c) Quercus semecarpifolia or Kharsu Oak (FT3; between 2,418-3,540 m asl) were selected on different ridge tops in Bhagirathi catchment area of Garhwal Himalaya. A total of 91 plant species including 23 trees (8 gymnosperms and 15 angiosperms), 21 shrubs and 47 herbs species belonging to 46 families were recorded from all the ridge top Oak forests. The highest mean tree density ($607{\pm}33.60trees\;ha^{-1}$) was observed in Q. floribunda forest with lower mean total basal cover (TBC) value ($48.02{\pm}3.67m^2ha^{-1}$), whereas highest TBC value ($80.16{\pm}3.30m^2ha^{-1}$) was recorded for Q. semecarpifolia forest, with lowest mean stem density ($594{\pm}23.43stems\;ha^{-1}$). The total biomass density (TBD) across three Oak forests ranged between $497.32{\pm}83.70$ (FT1) and $663.16{\pm}93.85t\;ha^{-1}$ (FT3), while the total carbon density (TCD) values ranged between $228.75{\pm}22.27$ (FT1) and $304.31{\pm}18.12t\;ha^{-1}$ (FT3). Most of the tree species were found with good regeneration (GR) status (average 45%) in all the forest types whereas, few species were found not regenerating (NR) (average 17%) however, few new recruitments were also recorded. ANOVA (Post-Hoc Tukey's test at 5% significance level) indicated significant forest-wise differences in TBC, TBD and TCD (in tree layer); family and evenness (in shrub layer only) values, while insignificant differences were noticed in density values of tree, seedling and herb layer.

Disturbance, Diversity, Regeneration and Composition in Temperate Forests of Western Himalaya, India

Tiwari, Om Prakash,Sharma, Chandra Mohan,Rana, Yashwant Singh,Krishan, Ram Institute of Forest Science 2019 Journal of Forest Science Vol.35 No.1

We have investigated the impact of anthropogenic and natural disturbances on regeneration, composition and diversity in some temperate forests of Bhagirathi Catchment Area of Garhwal Himalaya. The forests were categorized on the basis of canopy cover and magnitude of disturbance into highly, moderately and least disturbed classes. The dominant tree species at lower elevation were Pinus roxburghii and Quercus leucotrichophora, while Abies pindrow, Q. semecarpifolia and Rhododenron arboreum were the dominant species at the upper elevational forests. Cythula tomentosa and Indegophera heterentha were the dominant shrub species present in all the forests. Similarly, Circium wallichii and Oxalis corniculata were the dominant herb species found in all forests (except Q. leucotrichophora forest), whereas Thalictrum foliolosum and Viola pilosa were noticed in each forest (except P. roxburghii forest). The tree density values oscillated between $400{\pm}10\;trees\;ha^{-1}$ to $750{\pm}89.1\;trees\;ha^{-1}$ which generally decreased from lower to higher disturbance regimes however, the total basal cover value was highest ($88.1{\pm}23.6m^2\;ha^{-1}$) in highly disturbed forest and lowest ($25.8{\pm}2.2m^2\;ha^{-1}$) in moderately disturbed forest. The shrub and herb densities were maximum in least disturbed forest, while the young regenerating individuals i.e., sapling and seedling were observed increasing from high to low disturbed forests which reflected that the forest fragmentation adversely affected the regeneration. However, A. pindrow and P. roxburghii were found invariably encroaching the habitats of R. arboreum and Q. leucotrichophora at various altitudes, respectively. The Canonical Correspondence Analysis clearly indicated that the elevation and lopping intensity have more impact on trees, while shrub and herbs were more influenced by elevation, canopy cover, light attenuation and soil erosion. Pinus roxburghii was the only species which was affected by heavy litter removal and forest fire.

Plant Diversity, Tree Regeneration, Biomass Production and Carbon Storage in Different Oak Forests on Ridge Tops of Garhwal Himalaya

Chandra Mohan Sharma,Om Prakash Tiwari,Yashwant Singh Rana,Ram Krishan,Ashish Kumar Mishra 강원대학교 산림과학연구소 2016 Journal of Forest Science Vol.32 No.4

The present study was conducted on ridge tops of moist temperate Oak forests in Garhwal Himalaya to assess the plant diversity, regeneration, biomass production and carbon assimilation in different Oak forests. For this purpose, three Oak forest types viz., (a) Quercus leucotrichophora or Banj Oak (FT1; between 1,428-2,578 m asl), (b) Quercus floribunda or Moru Oak (FT2; between 2,430-2,697 m asl) and (c) Quercus semecarpifolia or Kharsu Oak (FT3; between 2,418-3,540 m asl) were selected on different ridge tops in Bhagirathi catchment area of Garhwal Himalaya. A total of 91 plant species including 23 trees (8 gymnosperms and 15 angiosperms), 21 shrubs and 47 herbs species belonging to 46 families were recorded from all the ridge top Oak forests. The highest mean tree density (607±33.60 trees ha-1) was observed in Q. floribunda forest with lower mean total basal cover (TBC) value (48.02± 3.67 m2ha-1), whereas highest TBC value (80.16±3.30 m2ha-1) was recorded for Q. semecarpifolia forest, with lowest mean stem density (594±23.43 stems ha-1). The total biomass density (TBD) across three Oak forests ranged between 497.32±83.70 (FT1) and 663.16±93.85 t ha-1 (FT3), while the total carbon density (TCD) values ranged between 228.75±22.27 (FT1) and 304.31±18.12 t ha-1 (FT3). Most of the tree species were found with good regeneration (GR) status (average 45%) in all the forest types whereas, few species were found not regenerating (NR) (average 17%) however, few new recruitments were also recorded. ANOVA (Post-Hoc Tukey’s test at 5% significance level) indicated significant forest-wise differences in TBC, TBD and TCD (in tree layer); family and evenness (in shrub layer only) values, while insignificant differences were noticed in density values of tree, seedling and herb layer.