• 대한의용생체공학회:의공학회지
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• 제36권5호
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• pp.198-203
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• 2015

The purpose of the study is to examine the effects of pacemaker location on cardiac pumping efficacy theoretically. We used a three-dimensional finite element cardiac electromechanical model of canine ventricles with models of the circulatory system. Electrical activation time for normal sinus rhythm and artificial pacing in apex, left ventricular free wall, and right ventricular free wall were obtained from electrophysiological model. We applied the electrical activation time maps to the mechanical contraction model and obtained cardiac mechanical responses such as myocardial contractile ATP consumption, stroke work, stroke volume, ejection fraction, and etc. Among three artificial pacing methods, left ventricle pacing showed best performance in ventricular pumping efficacy.

• Carbon letters
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• 제4권4호
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• pp.180-184
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• 2003

The role of KOH in the one-stage KOH-activation of rice straws was studied using FTIR, XPS, TGA, and DTG techniques. It was found that at the impregnation, KOH extracts to some extent the lignin component from rice straw and reacts with hydroxyl groups. On heat-treatment, the impregnated KOH facilitates intermolecular condensation reaction on one hand but retards the thermal degradation of cellulose molecules on the other hand. The oxygen-containing surface functional groups newly created by oxidation of KOH may facilitate the bulk, not controlled, consumption of carbon atoms so that the effective porosities may not be able to be developed by the one-stage activation process.

• 한국정보전자통신기술학회논문지
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• 제11권1호
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• pp.114-120
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• 2018

본 논문에서는 근전도 신호 획득 및 분석을 위한 웨어러블 디바이스용 센서 시스템을 구현하였다. 구현된 시스템의 성능은 임상용 근전도 시스템에서 획득된 근전도 신호와 근피로도 및 근활성도의 상관성 분석에 의해 평가되었으며 실측된 소비 전력이 상용 근전도 시스템들과 비교되었다. 5명의 피실험자들의 이두박근 및 삼두박근에서 수집된 근전도 신호를 통한 실험에서, 구현된 시스템이 임상용 근전도 센서 시스템과 근피로도는 1.1~1.4의 상관성을, 근활성도는 약 1.0의 강한 양의 상관 경향성을 보여주었다. 또한 소비전력의 비교에서 구현된 시스템의 소비전력이 상용 근전도 시스템보다 25%~50%의 감소하였다.

• 대한조선학회논문집
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• 제57권3호
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• pp.152-159
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• 2020

Ship owners had pursued higher benefits by demanding the new design and construction of ships with higher operational efficiency. There was a necessity for shipyards to suggest a more economical design and advanced operation concept in order to meet the demands. Especially, since BOG combustion and activation of the re-liquefaction unit had to be taken into account in ship design in addition to fuel oil and gas consumption, the evaluation of the operating efficiency considering the technological trends was necessary. In this paper, it was aimed to study the design philosophy and operation strategy by considering the effect of fuel oil and gas consumption, BOG combustion, and activation of the re-liquefaction unit on the operating cost for laden voyage according to ship speed, BOR, and activation of the re-liquefaction unit. For this purpose, the costs were acquired by conducting the sailing simulation of an LNGC based on a mathematical model including the maneuvering equations of motion. The design philosophy and operation strategy was reviewed in terms of the operating cost.

• 한국유기농업학회지
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• 제31권1호
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• pp.29-44
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• 2023

The activation of consumption of environment-friendly agricultural processed foods means not only the growth of environment-friendly agriculture, but also the development of related industries. Therefore, it is necessary to identify and apply the needs and purchasing attributes of environment-friendly agricultural processed food consumers. For this, survey was conducted to adult men and women in their 20s and 60s and a total of 200 copies were used for empirical analysis. In this study, the average difference between importance-satisfaction for purchase attributes of environment-friendly agricultural processed food was verified, and the IPA Matrix was prepared based on this. As a result, in terms of purchasing importance and satisfaction, it was found that those with no experience in purchasing environment-friendly agricultural processed foods regarded product, price, place, promotion as more important than those with experience in purchasing. In case of IPA, product and price factors were all important and satisfactory regardless of purchasing experience. On the other hand, it was found that the key factors for promotion were neither important nor satisfied with consumers regardless of their purchasing experience. Therefore, it is mainly necessary to focus on marketing and mass media promotion. At the same time, various domestic and foreign best practices should be benchmarked and a 4P marketing strategy should be established and promoted.

• 한국환경과학회지
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• 제32권1호
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• pp.57-65
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• 2023

The advanced oxidation treatment using persulfate and zero-valent iron (ZVI) has been evaluated as a very effective technology for remediation of soil and groundwater contamination. However, the high rate of the initial reaction of persulfate with ZVI causes over-consumption of an injected persulfate, and the excessively generated active species show a low transfer rate to the target pollutant. In this study, ZVI was modified using selenium with very low reactivity in the water environment with the aim of controlling the persulfate activation rate by controlling the reactivity of ZVI. Selenium-modified ZVI (Se/ZVI) was confirmed to have a selenium coating on the surface through SEM/EDS analysis, and low reductive reactivity to trichlroethylene (TCE) was observed. As a result of inducing the persulfate activation using the synthesized Se/ZVI, the persulfated consumption rate was greatly reduced, and the decomposition rate of the model contaminant, anisole, was also reduced in proportion. However, the final decomposition efficiency was rather increased, which seems to be the result of preventing persulfate over-consumption. This is because the transfer efficiency of the active species (SO4-∙) of persulfate to the target contaminant has been improved. Selenium on the surface of Se/ZVI was not significantly dissolved even under oxidation conditions by persulfate, and most of it was present in the form of Se/ZVI. It was confirmed that the persulfate activation rate could be controlled by controlling the reactivity of ZVI, which could greatly contribute to the improvement of the persulfate oxidation efficiency.

• 한국생활과학회지
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• 제14권4호
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• pp.593-611
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• 2005

The purpose of this study is to explore the consumption cultural meaning of Community Currency Movement - a substitute currency institution - through an analysis of consumption behaviors and attitudes of Hanbat-LETS participants, who are recognized as the most active among Korea Community Currency Movements. The analytical method adopted in this study is the participation and observation method, along with the Focus Group Interview. Major findings are as follows: Hanbat-LETS participants experienced the following consumption behaviors and attitudes: economical consumption behavior creating the currency value, sustainable consumption behavior, consumption behavior shared with community, consumption behavior free from the need of competition and ownership, satisfaction from offering one's property, equal status and relationship among members, merry and happy attitude toward life. Community Currency Movement implies the consumption cultural meaning as followings: emergence of alienation through the realization of community society, practice of environment-friendly value, activation of region economy, development of one's ability and means of redemption of unemployment, construction of trustworthy society via trust.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.3821-3841
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• 2019

Cloud radio access networks (C-RANs) have been regarded in recent times as a promising concept in future 5G technologies where all DSP processors are moved into a central base band unit (BBU) pool in the cloud, and distributed remote radio heads (RRHs) compress and forward received radio signals from mobile users to the BBUs through radio links. In such dynamic environment, automatic decision-making approaches, such as artificial intelligence based deep reinforcement learning (DRL), become imperative in designing new solutions. In this paper, we propose a generic framework of autonomous cell activation and customized physical resource allocation schemes for energy consumption and QoS optimization in wireless networks. We formulate the problem as fractional power control with bandwidth adaptation and full power control and bandwidth allocation models and set up a Q-learning model to satisfy the QoS requirements of users and to achieve low energy consumption with the minimum number of active RRHs under varying traffic demand and network densities. Extensive simulations are conducted to show the effectiveness of our proposed solution compared to existing schemes.

• 한국생활과학회지
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• 제16권2호
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• pp.349-365
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• 2007

The purpose of this study was to explore the Korean housewives' consumption experiences and perceived quality of life. Perceived quality of life was composed of four dimensions: motivation, affect, efficiency, and activation. The study results are: 1. Housewives spare their time for physiologic activities(22.9%), household activities(20.1), and personal activities(10.1%) in sequence. 2. Although the motivation that housewives do shopping activities is coming from a sense of duty, the perceived quality of life during shopping is showing far more positive affect than the perceived quality of life during other activities. In this context, shopping activities are interesting in that they are thought of a kind of entertainment as well as work. 3. With an analysis of covariance, housewives' perceived quality of life has an effect on everyday life in that 4 perceived qualities of life such as motivation, affect, efficiency and activation has a significant effect on flow and it has a significant effect on satisfaction.

• ETRI Journal
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• 제38권5호
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• pp.885-895
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• 2016

The lowest power mode (passive-standby mode) was proposed for reducing the power consumption of set-top boxes in a standby state when not receiving content. However, low-power set-top boxes equipped with the lowest power mode have been rarely commercialized because of their low-quality user experience. In the lowest power mode, they deactivates almost all of operational modules and processes, and thus require dozens of seconds for activation latency (that is, the latency for activating all modules of the set-top boxes in a standby state). They are not even updated in a standby state because they deactivate their network interfaces in a standby state. This paper proposes an adaptive standby mode scheduling method for improving the user experience of such boxes. Set-top boxes using the proposed method can analyze the activation pattern and find the frequently used time period (that is, when the set-top boxes are frequently activated). They prepare for their activation during this frequently used time period, thereby reducing the activation latency and enabling their update in a standby state.