• KIPS Transactions on Computer and Communication Systems
• /
• v.9 no.4
• /
• pp.83-88
• /
• 2020

In Solar-powered wireless sensor networks(SP-WSN), the battery is periodically charged, so the best use of harvested energy is more important, rather than minimizing energy consumption. Meanwhile, as is well known, the reliability of communication between sensor nodes is very limited due to the resource-constraint of sensor nodes. In this paper, we propose an advanced FEC (forward error correction) scheme which can give SP-WSN more reliability for communication. Firstly, the proposed scheme uses energy modeling to calculate the amount of surplus energy which can be utilized for extra operations, and then determines the number of additional parity bits according to this amount of surplus energy. At the same time, link quality modeling calculates the optimal parity bits for error recovery in the current data communication environment. Finally, by considering these two parity sizes, it is possible to determine the optimal parity size that can maximize the data reliability without affecting the node black out. Performance verification was performed by comparing the amount of data collected at the sink and the number of outage nodes with other schemes.

• Journal of KIISE:Computer Systems and Theory
• /
• v.36 no.5
• /
• pp.360-370
• /
• 2009

Using solar power in wireless sensor networks requires a different approach to energy optimization from networks with battery-based nodes. Solar energy is an inexhaustible supply which can potentially allow a system to run forever, but there are several issues to be considered such as the uncertainty of energy supply and the constraint of rechargeable battery capacity. In this paper, we present SolarSS: a reliable storage system for solar-powered sensor networks, which provides a set of functions, in separate layers, such as sensory data collection, replication to prevent failure-induced data loss, and storage balancing to prevent depletion-induced data loss. SolarSS adapts the level of layers activated dynamically depending on solar energy availability, and provides an efficient resource allocation and data distribution scheme to minimize data loss.

• Environmental and Resource Economics Review
• /
• v.26 no.1
• /
• pp.37-56
• /
• 2017

This study analyzed the mutual causal relationship between energy consumption, production, and export for manufacturing industry in Korea. The Korean manufacturing industry was divided into nine industries and panel data was constructed from 1991 to 2013. The panel Granger causality test method developed by Demitrescu and Hurlin (2012) was used along with the Vector Error Correction Model. This analysis showed that there was Granger Causality from production to energy consumption, from exports to energy consumption. However, Granger Causality was not established in the opposite direction. Therefore, this result supports the conservation hypothesis of Qzturk (2010) that energy-saving policies in the manufacturing sector can be implemented without adverse effects on production or exports in short-run. There is a long-run cointegrating relationship between production, energy consumption, exports, labor, and capital in the Korean manufacturing sector. Furthermore, the energy consumption contributes to the increasing of production in long-run equilibrium relationship.

• Journal of KIISE:Computer Systems and Theory
• /
• v.37 no.1
• /
• pp.55-59
• /
• 2010

Most applications for solar-powered wireless sensor networks are usually deployed in remote areas without a continuous connection to the external networks and a regular maintenance by an administrator. In this case, sensory data has to be stored in the network as much as possible until it is uploaded by the data mule. For this purpose, a balanced data distribution over the network should be performed, and this can be achieved efficiently by taking the amount of available energy and storage into account, in the system layer of each node. In this paper, we introduce a simple but very efficient data distribution algorithm, by which each solar-powered node utilizes the harvested energy and the storage space maximally. This scheme running on each node determines the amount of energy which can be used for a data distribution as well as the amount of data which should be transferred to each neighbor, by using the local information of energy and storage status.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.765-768
• /
• 2012

Recently, the supply ratio of smart devices application has become increasable, utilization of device increases constantly. At the same time, used application is more gentrified. However, using time of devices is decreased. To solve these problems, many research is studying about the hardware/software. One of them is profiling power consumption by process units. The process can be managed, based on measured energy consumption data. These means that it can efficiently use the residual energy. Application at the stage of program design can analyze and used-energy using the trace by considering the low-power can design. In this paper, we studied software-based power-metering framework for android platform. We survey each process-level power consumption measurement techniques, compare advantages and disadvantages of the technique and propose improved measures.

• Journal of Korea Technology Innovation Society
• /
• v.14 no.4
• /
• pp.736-760
• /
• 2011

The importance of new renewable energy is emphasized not only new growth engine but also the key solution for the exhaustion problem of fossil energy and environment problem. For the steady growth of new renewable energy industry, securing related labor force is an essential factor. In this study, the status on labor force of new renewable energy industry was identified and forecasted the labor force demand of new renewable energy in 2015 by reflecting the industrial growth outlook on the new renewable energy. For the quantitative analysis methodology, the stock approach of Bureau of Labor Statistics (BLS) of the United States was applied. Also by performing survey on the experts, the opinions of experts on supply and demand of new renewable energy labor force or worker training programs have been gathered. As a result of study, it has been analyzed that nearly 20% annual growth rate will be shown as the labor force demand in the field of new renewable energy industry increases from 14,100 people in 2010 to 33,200 people in 2015. In the survey on experts, we could find that a plan for supplying labor force must be prepared promptly in order to accomplish new renewable energy supply objectives and industrial growth objectives by our country in the future as the supply of new renewable energy labor force is currently insufficient. Also, it has been analyzed that the effort for deciding the proper new renewable energy labor force training program standard will be necessary. This study result could be used as a material of labor force training plan for the steady growth of new renewable energy industry in the future.

• Journal of Korean Home Economics Education Association
• /
• v.23 no.3
• /
• pp.121-138
• /
• 2011

This research examined the amounts and methods change of recommended energy intake(REI) from 1962's recommended dietary intakes for Korean to 2010's dietary reference intakes for Koreans. REI is composed of 3 factors, such basal metabolic rate(or Resting Energy Expenditure, REE), activity energy, and thermogenic effect of foods. The first 1962 calculation formula of REI was weight based formula, that of 95's was the weight based REE multiplied by activity coefficient, and the recent one of 2005's(Estimated Energy Requirement: EER) was age, height. weight, and the activity level applying formula derived from the energy expenditure data by doubly labeled water technique(DLW). During the 50 years or so, REIs were reduced in all age groups, according to the activity(labor) strength and hour were reduced. The individual REI calculation method was introduced in 1995, and individual REI calculation was recommended since to prevent obesity. For the better REI estimation for Koreans, REI calculation formula derived from our peoples' DLW energy expenditure data is required.

• Journal of the Korea Convergence Society
• /
• v.11 no.6
• /
• pp.173-182
• /
• 2020

Since 2000, Korea has seen a big trend in the market, as the EU tightened regulations on environment due to global warming, high oil prices and aging rural population distribution, strengthening the need for multi-purpose electric moto vehicles for small farmers based on eco-friendly energy. Multi-purpose electric motor vehicles for rural small businesses will be a very innovative means of transportation, not only maintained at a low cost and to reduce greenhouse gases through the activation of eco-friendly energy, but also be a very innovative means of transportation for reducing the labor intensity of the aging farming industry and transporting night work and logistics. In this paper, with the implementation of eco-friendly energy policies, small and medium-sized rural small business owners can easily operate on unpaved roads and well-drawn farming environments, while the intensity of labor can be reduced when transporting crops also can simply replace parts at a low cost in the event of an accident. To propose rural multi-purpose modular electric vehicles, the existing literature is reviewed and 12 modular parts are presented by benchmarking electric vehicles at home and abroad. This paper is thought to be helpful for the research of the industry as well as the design industry of modular electric vehicles.

• Environmental and Resource Economics Review
• /
• v.27 no.1
• /
• pp.29-66
• /
• 2018

This study constructs an energy-extended KLEM DB of 35 Korean industries, and estimates the elasticities of substitution under various nesting structures of production technologies. Unlike most existing studies that employed only three inputs, K, L, and E, we applied a dual approach where non-energy intermediate input M is also incorporated as a production input. Our dual approach which extended that of van der Werf (2008)'s 3-input model successfully identified and estimated the multi-nested production functions. We provide the estimates of the elasticities of substitution among 4 different energy sources as well. Our estimation results would be used for energy-environment model building for Korea.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.126.2-126.2
• /
• 2010

The "grafting from" technology to prepare the well-defined microphase-separated structure of polymer using atom transfer radical polymerization (ATRP) will be introduced in this presentation. Various amphiphilic comb copolymers were synthesized through this approach using poly (vinylidene fluoride) (PVDF), poly (vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-co-CTFE) and poly(vinyl chloride) (PVC) as a macroinitiator. Hydrophilic side chains such as poly (styrene sulfonic acid) (PSSA) or poly (sulfopropyl methacrylate) (PSPMA) were grafted from the mains chains using direct initiation of the chlorine atoms. The structure of mass transport channels has been controlled and fixed by crosslinking the hydrophobic domains, which also provides the greater mechanical properties of membranes. Successful synthesis and microphase-separated structure of the polymer were confirmed by $^1H$ NMR, FT-IR spectroscopy and TEM. The grafted/crosslinked membranes exhibited good mechanical properties (400 MPa of Young's modulus) and high thermal stability (up to $300^{\circ}C$), as determined by a universal testing machine (UTM) and TGA, respectively.