Review of Simultaneous Wireless Information and Power Transfer in Wireless Sensor Networks

Asiedu, Derek Kwaku Pobi,Shin, Suho,Koumadi, Koudjo M.,Lee, Kyoung-Jae The Korea Institute of Information and Commucation 2019 Journal of information and communication convergen Vol.17 No.2

Recently, there has been an increase in research on wireless sensor networks (WSNs) because they are easy to deploy in applications such as internet-of-things (IoT) and body area networks. However, WSNs have constraints in terms of power, quality-of-service (QoS), computation, and others. To overcome the power constraint issues, wireless energy harvesting has been introduced into WSNs, the application of which has been the focus of many studies. Additionally, to improve system performance in terms of achievable rate, cooperative networks are also being explored in WSNs. We present a review on current research in the area of energy harvesting in WSNs, specifically on the application of simultaneous wireless information and power transfer (SWIPT) in a cooperative sensor network. In addition, we discuss possible future extensions of SWIPT and cooperative networks in WSNs.

Vietnamese Health Care Providers' Preferences Regarding Recommendation of HPV Vaccines

Asiedu, Gladys B,Breitkopf, Carmen Radecki,Kremers, Walter K,Ngo, Quang V,Nguyen, Nguyen V,Barenberg, Benjamin J,Tran, Vinh D,Dinh, Tri A Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

Physician recommendation is an important predictor of HPV vaccine acceptance; however, physician willingness and preferences regarding HPV vaccination may be influenced by factors including patient age, vaccine type, and cost. A cross-sectional survey was administered to a convenience sample of health care providers in Da Nang, Vietnam, to evaluate awareness, perceptions about HPV and HPV vaccines, and willingness to vaccinate a female patient. Willingness to vaccinate was evaluated using a full-factorial presentation of scenarios featuring the following factors: vaccine cost (free vs 1,000,000 VND), patient age (12, 16, or 22 years), and HPV vaccine type (bivalent vs quadrivalent). Responses from 244 providers were analyzed; providers had a mean age of $34{\pm}11.9$ years; a majority were female, married, and had children of their own. Thirty-six percent specialized in obstetrics/gynecology and 24% were providers in family medicine. Of the three factors considered in conjoint analysis, vaccine cost was the most important factor in willingness to vaccinate, followed by patient age, and vaccine type. The most favorable scenario for vaccinating a female patient was when the vaccine was free, the patient was 22 years of age, and the HPV4 vaccine was described. In multivariable analysis, older age, being a physician, being married, and having children were all associated with increased willingness to recommend HPV vaccination (p<0.05). Provider willingness is an important aspect of successful HPV vaccination programs; identifying preferences and biases in recommendation patterns will highlight potential areas for education and intervention.

가나동부지역에서 곡물건조를 위한 농업부산물 바이이오매스 활용방안 연구

아피아어거스틴 ( Augustine Asiedu Appiah ),홍성구 ( Seonggu Hong ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

Storage losses have been found to be the major contributing factor to postharvest losses of crops in Ghana. This is mostly brought about by mould and insect infestation partly due to unsafe moisture levels of products for storage. Agricultural residues are generated in larger quantities in the eastern region of Ghana are mostly burnt to make way for subsequent farming seasons. This research studies the use of these residues (maize cobs, rice husks, groundnut kernels and cassava stems) as fuel for the drying of major commodities as maize, groundnut and cassava in the eastern region of Ghana and the resulting reduction in deforestation and carbon emissions. The energy consumption of some biomass-fed dryers was used to estimate the drying energy demand for these available commodities. The biomass-fed dryers considered included Dryer1 (Tran et al., 2015), Dryer2 (Dhasnushkodi et al., 2015), Dryer3 (Gunathilake, 2018) with consumption per ton of moisture removal as 5.8GJ, 14.3GJ and 19.86GJ respectively. The average energy demands per district for drying of the referred commodities were found to be 65087GJ, 143051GJ and 198886GJ for Dryer1, Dryer2 and Dryer3 respectively. The residues were estimated from the crops production figures and the residue to product ratio of 0.29, 0.26, 0.37 and 0.192 for maize cobs, rice husks, groundnut kernels and cassava stems respectively. The estimated average annual residues generated per district were 4240Mt, 324Mt, 156Mt and 40238Mt for maize cobs, rice husks, groundnut kernels and cassava stems respectively. 67977GJ, 3651GJ, 2161GJ and 127964GJ were estimated to be the energies to be realized annually in every district for the residues in respective order as stated previously. It was realized that for dryer 1, energies from only maize cobs, rice husks and groundnut kernels will be enough to dry commodities unlike dryers 2 and 3. A storage system and optimization strategy for full utilization of those residues will be proposed. An assessment of the reduction of carbon emissions as a result of the use of available residues rather than fossil fuels will be done. The reduction is expected to be significant to impact positively on the environment.

가나 동부지역에서 곡물 건조를 위한 농업부산물 바이이오매스 활용방안 연구

어거스틴아시우드아피아 ( Augustine Asiedu Appiah ),홍성구 ( Hong Seong-gu ) 한국농공학회 2019 한국농공학회 학술대회초록집 Vol.2019 No.-

Storage losses have been found to be the major contributing factor to postharvest losses crops in Ghana. This is mostly brought about by mould and insect infestation partly due to unsafe moisture levels of products for storage. Agricultural residues are generated in larger quantities in the eastern region of Ghana and mostly burnt to make way for subsequent farming seasons. This research studies the use of these residues (maize cobs, rice husks, groundnut kernels and cassava stems) as fuel for the drying of major commodities as maize, groundnut and cassava in the eastern region of Ghana and the resulting reduction in deforestation and carbon emissions. The energy consumption of some biomass-fed dryers was used to estimate the drying energy demand for these available commodities. The biomass-fed dryers considered included Dryer1 (Tran et al., 2015), Dryer2 (Dhasnushkodi et al., 2015), Dryer3 (Gunathilake, 2018) with consumption per ton of moisture removal as 5.8GJ, 14.3GJ and 19.86GJ respectively. The average energy demands per district for drying of the referred commodities were found to be 65087GJ, 143051GJ and 198886GJ for Dryer1, Dryer2 and Dryer3 respectively. The residues were estimated from the crops production figures and the residue to product ratio of 0.29, 0.26, 0.37 and 0.192 for maize cobs, rice husks, groundnut kernels and cassava stems respectively. The estimated average annual residues generated per district were 4240Mt, 324Mt, 156Mt and 40238Mt for maize cobs, rice husks, groundnut kernels and cassava stems respectively. 67977GJ, 3651GJ, 2161GJ and 127964GJ were estimated to be the energies to be realized annually in every district for the residues in respective order as stated previously. It was realized that for dryer 1, energies from only maize cobs, rice husks and groundnut kernels will be enough to dry commodities unlike dryers 2 and 3. A storage system and optimization strategy for full utilization of those residues will be proposed. An assessment of the reduction of carbon emissions as a result of the use of available residues rather than fossil fuels will be done. The reduction is expected to be significant to impact positively on the environment.

Understanding the Underlying Reasons behind Time Overruns of Government Building Projects in Ghana

Richard O. Asiedu,Hans W. Alfen 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.6

Time overruns are common occurrences in the Ghanaian Construction Industry (GCI), inevitably resulting in budget overruns and eventual project abandonment. This paper presents the findings of a survey which aimed at exploring the severity, frequency and significant Critical Failure Factors (CFF) engendering time overruns in public building projects in Ghana. Thirty CFF were identified based on a two-tier strategy - extensive review of extant literature and exploratory interviews. A total of 240 structured questionnaires were administered to the three key stakeholders within the GCI - clients, consultants and contractors. Based on a response rate of 55%, the five most important factors that engender time overruns have been identified - recurrent default of interim payment by government, government’s refusal to pay local for interest on delayed payments, lengthy payment processes resulting in delays, difficulty in arranging for extra funds when projects exceed their initial budget and interference, bribery and conflict of interest in the selection of contractors. The results of a Spearman’s rank correlation test showed no difference in the viewpoints of the key respondents. The results of this paper have highlighted the widely held belief that most government contracts are poorly planned in the mist of government’s fiscal constraints. It is expected that the findings will provide deeper insight into the underlying factors influencing time overruns and provide pointers towards averting project delays.

Behaviour of students on social media sites : The Ghanaian Context

Nasir Koranteng Asiedu 건국대학교 GLOCAL(글로컬)캠퍼스 지식콘텐츠연구소 2023 International Journal of Knowledge Content Develop Vol.13 No.2

Behaviour on social media sites need to be clearly defined so that students would know the clear distinction between the acceptable and unacceptable acts they are supposed to exhibit whenever they get on social media platforms. With the adoption of the survey approach, this study randomly selected 204 students from two renowned universities in Ghana to participate in the study. Using the theory of Technological Determinism, the results of this study indicated that technology has the power to influence human behaviour in a positive and negative manner. The results also brought out the acceptable and unacceptable behaviour that should or should not be exhibited on social media sites by students. The study established the importance of the theory of Technological Determinism to media use. It also gave a vivid description of what is right and not right on social media sites.

Performance Comparison of Single-Carrier and Multi-Carrier Systems in a Terahertz Wireless Communication Environment

Derek Kwaku Pobi Asiedu,Roger Kwao Ahiadormey2,신수호,이경재 한국정보기술학회 2019 JOURNAL OF ADVANCED INFORMATION TECHNOLOGY AND CON Vol.9 No.1

This paper investigates the performance comparison of a Terahertz (THz) communications for a single-carrier and a multi-carrier single antenna point-to-point communication system. The multi-carrier system and single carrier system consider the orthogonal frequency division multiplexing (OFDM) and the minimum mean square error linear equalizer (MMSE-LE), respectively. We compare the frame-error-rate (FER) and throughput performance of both the systems for a THz communication environment with the carrier frequency of 300GHz and the tapped delay line (TDL) channel models described in 3GPP. It is observed from the simulation results that the OFDM systems outperform the MMSE-LE for various configurations.

Two-Way Hybrid Power-Line and Wireless Amplify-and-Forward Relay Communication Systems

Derek Kwaku Pobi Asiedu,Roger Kwao Ahiadormey2,신수호,이경재 한국정보기술학회 2019 JOURNAL OF ADVANCED INFORMATION TECHNOLOGY AND CON Vol.9 No.1

Power-line communication (PLC) has influenced smart grid development. In addition, PLC has also been instrumental in current research on internet-of-things (IoT). Due to the implementation of PLC in smart grid and IoT environments, strides have been made in PLC and its combination with the wireless system to form a hybrid communication system. Also, PLC has evolved from a single-input-single-output (SISO) configuration to multiple-input-multiple-output (MIMO) configuration system, and from a point-to-point communication system to cooperative communication systems. In this work, we extend a MIMO wireless two-way amplify-and-forward (AF) cooperative communication system to a hybrid PLC and wireless (PLC/W) system configuration. We then maximize the weighted sum-rate for the hybrid PLC/W by optimizing the precoders at each node within the hybrid PLC/W system. The sum-rate problem was found to be non-convex, therefore, an iterative algorithm is used to find the optimal precoders that locally maximize the system sum-rate. For our simulation results, we compare our proposed hybrid PLC/W configuration to a PLC only and wireless only configuration at each node. Due to an improvement in system diversity, the hybrid PLC/W configuration outperformed the PLC only and wireless only system configurations in all simulation results presented in this paper.

전력선 통신 및 무선통신 협력시스템에 대한 보안용량 분석

김건주,Derek Kwaku Pobi Asiedu,이경재 한국통신학회 2019 한국통신학회 학술대회논문집 Vol.2019 No.1

A Biostimulant Preparation of Brown Seaweed Ascophyllum nodosum Suppresses Powdery Mildew of Strawberry

Sruti Bajpai,Pushp Sheel Shukla,Samuel Asiedu,Kris Pruski,Balakrishnan Prithiviraj 한국식물병리학회 2019 Plant Pathology Journal Vol.35 No.5

Strawberry, an important fruit crop, is susceptible to a large number of pathogens that reduce fruit quality and productivity. In this study, the effect of a biostimulant prepared from Ascophyllum nodosum extract (ANE) (0.1%, 0.2%, and 0.3%) was evaluated on powdery mildew progression under greenhouse and field conditions. In the greenhouse, application of 0.2% ANE showed maximum reduction in powdery mildew progression as compared to the control. Forty-eight hour post-inoculation, foliar spray of 0.2% ANE reduced spore germination by 75%. Strawberry leaves sprayed with ANE showed higher total phenolic and flavonoid content in response to powdery mildew infection. Furthermore, application of ANE elicited defense response in strawberry plants by induction of defense-related enzymes, such as phenylalanine ammonia lyase, polyphenol oxidase, and peroxidase activity. In field conditions, foliar spray of 0.2% ANE showed a reduction of 37.2% of natural incidence of powdery mildew infection as compared to the control. ANE sprayed plant also reduces the severity of powdery mildew infection under natural conditions. These results indicate that application of ANE induces the strawberry plant’s active defense against powdery mildew infection by induction of secondary metabolism and regulating the activities of defense-related enzymes.