Novel Design of a Bandwidth Enhanced and Frequency Reconfigurable, Wearable Antenna for Body Centric Communication

Devendra Kumar,Dhirendra Mathur 한국전자파학회 2024 Journal of Electromagnetic Engineering and Science Vol.24 No.3

This paper proposes a novel design for a frequency reconfigurable and bandwidth-enhanced antenna for use in biomedical telemetry appli- cations. Data pertaining to a patient’s body parameters, such as blood pressure, pulse, and temperature, are gathered using sensors and then transmitted to a remote place for monitoring. The proposed antenna is connected to a wearable transmitter, which transfers the body parameter data to a centrally located nearby control unit. The antenna operates in the 5.8 GHz band in single-band mode and in the 4.27 GHz (C band) and 5.8 GHz industrial, scientific, and medical (ISM) bands in dual-band mode. The use of ethylene-vinyl acetate foam as a substrate makes the structure waterproof and ultraviolet resistant. The basic antenna structure equipped with proximity coupling offers a front-to-back ratio (FBR) of 17.62 dB and a bandwidth of 122 MHz. With an additional upper patch and resonant slots, bandwidth en- hancement of 82.85% and 11.57% improvement in the FBR are achieved, respectively. Overall, a maximum FBR of 19.66 dB and gain of 5.0 dBi are attained over the resonant frequency. The specific absorption rate is found to be 0.145 W/kg for 10 gram of tissue.

Investments on Pro-poor Development Projects on Goats: Ensuring Success for Improved Livelihoods

Devendra, C. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.1

The elements that determine the success of development projects on goats and the prerequisites for ensuring this are discussed in the context of the bewildering diversity of goat genetic resources, production systems, multifunctionality, and opportunities for responding to constraints for productivity enhancement. Key determinants for the success of pro-poor projects are the imperatives of realistic project design, resolution of priorities and positive impacts to increase investments and spur agricultural growth, and appropriate policy. Throughout the developing world, there exist 97% of the total world population of 921 million goats across all agroecological zones (AEZs), including 570 breeds and 64% share of the breeds. They occupy a very important biological and socioeconomic niche in farming systems making significant multifunctional contributions especially to food, nutrition and financial security, stability of farm households, and survival of the poor in the rural areas. Definitions are given of successful and failed projects. The analyses highlighted in successful projects the value of strong participatory efforts with farmers and climate change. Climate change effects on goats are inevitable and are mediated through heat stress, type of AEZ, water availability, quantity and quality of the available feed resources and type of production system. Within the prevailing production systems, improved integrated tree crops - ruminant systems are underestimated and are an important pathway to enhance C sequestration. Key development strategies and opportunities for research and development (R and D) are enormous, and include inter alia defining a policy framework, resolution of priority constraints using systems perspectives and community-based participatory activities, application of yield-enhancing technologies, intensification, scaling up, and impacts. The priority for development concerns the rainfed areas with large concentrations of ruminants in which goats, with a capacity to cope with heat tolerance, can be the entry point for development. Networks and networking are very important for the diffusion of information and can add value to R and D. Well formulated projects with clear priority setting and participatory R and D ensure success and the realisation of food security, improved livelihoods and self-reliance in the future.

RELATIONS OF DAGUM DISTRIBUTION BASED ON DUAL GENERALIZED ORDER STATISTICS

Devendra Kumar 한국전산응용수학회 2017 Journal of applied mathematics & informatics Vol.35 No.5

The dual generalized order statistics is a unified model which contains the well known decreasingly ordered random variables like order statistics and lower record values. With this definition we give simple expressions for single and product moments of dual generalized order statistics from Dagum distribution. The results for order statistics and lower records are deduced from the relations derived and some computational works are also carried out. Further, a characterizing result of this distribution on using the conditional moment of the dual generalized order statistics is discussed. These recurrence relations enable computation of the means, variances and covariances of all order statistics for all sample sizes in a simple and efficient manner. By using these relations, we tabulate the means, variances, skewness and kurtosis of order statistics and record values of the Dagum distribution.

Retrieval of Distally Migrated Coils with Detachable Intracranial Stent during Coil Embolization of Cerebral Aneurysm

Devendra Pal Singh,Soon Chan Kwon,Lijin Huang,Won Joo Lee 대한뇌혈관외과학회 2016 Journal of Cerebrovascular and Endovascular Neuros Vol.18 No.1

Migration of coils during endovascular procedures is a rare, but well-known complication. We are reporting two cases of successfully retrieving migrated coil using detachable intracranial stent. In both of our cases there was distal migration of coil during the intracranial aneurysm coiling procedure. The Solitaire® AB stent (Covidien, Irvine, CA, USA) was used to retrieve those coils. The stent was passed distal to the migrated coil using standard technique. It was then partially deployed and gradually withdrawn along with the entangled coil. Coil retrieval using the fully retrievable intracranial stent is a very simple, safe and easily available alternative for retrieval of distally migrated coil.

MOMENTS OF LOWER GENERALIZED ORDER STATISTICS FROM DOUBLY TRUNCATED CONTINUOUS DISTRIBUTIONS AND A CHARACRERIZATIONS

Devendra Kumar 충청수학회 2013 충청수학회지 Vol.26 No.3

In this paper, we derive recurrence relations for moments of lower generalized order statistics within a class of doubly truncated distributions. Inverse Weibull, exponentiated Weibull,power function, exponentiated Pareto, exponentiated gamma, generalized exponential, exponentiated log-logistic, generalized inverse Weibull, extended type I generalized logistic, logistic and Gumble distributions are given as illustrative examples. Further, recurrence relations for moments of order statistics and lower record values are obtained as special cases of the lower generalized order statistics,also two theorems for characterizing the general form of distribution based on single moments of lower generalized order statistics are given.

Performance Enhancement of a Refrigerator Using Phase Change Material-Based Condenser: An Experimental Investigation

Devendra Dandotiya,N. D. Banker 대한설비공학회 2017 International Journal Of Air-Conditioning and Refr Vol.25 No.4

Tropical countries like India, the ambient temperature reaches to 45–50 ∘ C in the summer and higher ambient temperature directly impacts the energy required by the household refrigerator. This paper presents an experimental performance of a domestic refrigerator incorporated with a phase change material (PCM)-based condenser in parallel to the conventional wire-and-tube air-cooled condenser for the climatic conditions of India. It is proposed to operate the refrigerator with the PCM-based condenser, while the ambient temperature is higher during the day, otherwise with the air-cooled condenser. Due to large latent heat storage capacity of the PCM, the condenser temperature would not increase significantly. The COP of the PCM-based condenser was 28% higher as compared to air cooled condenser for 60 min which reduce to 3% as PCM temperature reached to 33 ∘C. The energy consumption is lower by ∼15 ∼15 % in 3 12 312h of refrigerator experimentation with the proposed modification.

Food-Feed Systems in Asia - Review -

Devendra, C.,Sevilla, C.,Pezo, D. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.5

This review paper discusses the relevance and potential importance of food-feed systems in Asian agricultural systems, and in particular the role and contribution of legumes to these systems. A food-feed system is one that maintains, if not increases, the yield of food crops, sustains soil fertility, and provides dietary nutrients for animals. It involves a cropping pattern within which the feed crop has many beneficial effects without competing for land, soil nutrients and water with the food crops. The agricultural environment is described with reference to the priority agro-ecological zones and prevailing mixed farming systems in Asia. Within these systems, animal production is severely hampered by critical feed shortages which can however, be alleviated by the integration of suitable leguminous forages into the cropping systems. The review also focuses on the role and potential importance of leguminous forages in terms of biodiversity, their uses in farming systems, beneficial effects on animal performance, and draws attention to six case studies in different countries that clearly demonstrate many benefits of developing such food-feed systems. Considerable opportunities exist for widening the use of forage legumes in the development of systems with several complementary advantages (e.g. fenceline, cover crops, fodder banks, forage source and erosion control) to improve the development of sustainable crop-animal systems in Asia.

Feed Resources for Animals in Asia: Issues, Strategies for Use, Intensification and Integration for Increased Productivity

Devendra, C.,Leng, R.A. Asian Australasian Association of Animal Productio 2011 Animal Bioscience Vol.24 No.3

The availability and efficient use of the feed resources in Asia are the primary drivers of performance to maximise productivity from animals. Feed security is fundamental to the management, extent of use, conservation and intensification for productivity enhancement. The awesome reality is that current supplies of animal proteins are inadequate to meet human requirements in the face of rapidly depleting resources: arable land, water, fossil fuels, nitrogenous and other fertilisers, and decreased supplies of cereal grains. The contribution of the ruminant sector lags well behind that of non-ruminant pigs and poultry. It is compelling therefore to shift priority for the development of ruminants (buffaloes, cattle, goats and sheep) in key agro-ecological zones (AEZs), making intensive use of the available biomass from the forage resources, crop residues, agro-industrial by-products (AIBP) and other non-conventional feed resources (NCFR). Definitions are given of successful and failed projects on feed resource use. These were used to analyse 12 case studies, which indicated the value of strong participatory efforts with farmers, empowerment, and the benefits from animals of productivity-enhancing technologies and integrated natural resource management (NRM). However, wider replication and scaling up were inadequate in project formulation, including systems methodologies that promoted technology adoption. There was overwhelming emphasis on component technology applications that were duplicated across countries, often wasteful, the results and relevance of which were not clear. Technology delivery via the traditional model of research-extension linkage was also inadequate, and needs to be expanded to participatory research-extension-farmer linkages to accelerate diffusion of technologies, wider adoption and impacts. Other major limitations concerned with feed resource use are failure to view this issue from a farming systems perspective, strong disciplinary bias, and poor links to real farm situations. It is suggested that improved efficiency in feed resource use and increased productivity from animals in the future needs to be cognisant of nine strategies. These include priorities for feed resource use; promoting intensive use of crop residues; intensification of integrated ruminant-oil palm systems and use of oil palm by-products; priority for urgent, wider technology application, adoption and scaling up; rigorous application of systems methodologies; development of adaptation and mitigation options for the effects of climate change on feed resources; strengthening research-extension-farmer linkages; development of year round feeding systems; and striving for sustainability of integrated farming systems. These strategies together form the challenges for the future.

Crop-Animal Production Systems in Tropical Regions - Review -

Devendra, C. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.2

Crop-animal systems which form the backbone of agriculture in the tropics are discussed with reference to their characteristics, economic importance of animals, genesis and types of crop-animal systems, relevance and potential importance, and priorities for research and development. These production systems are found across all agroecological zones: rain-fed temperate and highland systems, semi-arid and arid tropics, and sub-humid and humid tropics: the last four are priority areas in Asia. The potential importance of these systems in Asia is reflected in their advantages, synergism and complimentarity, economic benefits and contribution to sustainability. Illustrative case studies are cited which are appropriate to the two broad types of mixed farming systems: systems combining animals and annual cropping, and systems combining animals with perennial cropping with reference to Indonesia, Philippines, Malaysia, Sri Lanka, China and Nigeria. Priorities for research and development should address more complete use of the animal genetic resources, intensive utilisation of the feed resources, development-oriented utilisation of research results, minimizing animal diseases, and implementation of appropriate institutional and policy issues.

ON RELATIONS FOR QUOTIENT MOMENTS OF THE GENERALIZED PARETO DISTRIBUTION BASED ON RECORD VALUES AND A CHARACTERIZATION

Devendra Kumar 한국전산응용수학회 2013 Journal of applied mathematics & informatics Vol.31 No.3

Generalized Pareto distributions play an important role in reliability, extreme value theory, and other branches of applied probability and statistics. This family of distribution includes exponential distribution, Pareto distribution, and Power distribution. In this paper we establish some recurrences relations satisfied by the quotient moments of the upper record values from the generalized Pareto distribution. Further a characterization of this distribution based on recurrence relations of quotient moments of record values is presented.