• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.198-206
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• 2024

Given the high theoretical capacity (1,675 mAh g^-1) and the inherent affordability and ubiquity of elemental sulfur, it stands out as a prominent cathode material for advanced lithium metal batteries. Traditionally, sulfur was sequestered within conductive porous carbons, rooted in the understanding that their inherent conductivity could offset sulfur's non-conductive nature. This study, however, pivots toward a transformative approach by utilizing diatom shell (DS, diatomite)-a naturally abundant and economically viable siliceous mineral-as a sulfur host. This approach enabled the development of a sulfurlayered diatomite/S composite (DS/S) for cathodic applications. Even in the face of the insulating nature of both diatomite and sulfur, the DS/S composite displayed vigorous participation in the electrochemical conversion process. Furthermore, this composite substantially curbed the loss of soluble polysulfides and minimized structural wear during cycling. As a testament to its efficacy, our Li-S battery, integrating this composite, exhibited an excellent cycling performance: a specific capacity of 732 mAh g^-1 after 100 cycles and a robust 77% capacity retention. These findings challenge the erstwhile conviction of requiring a conductive host for sulfur. Owing to diatomite's hierarchical porous architecture, eco-friendliness, and accessibility, the DS/S electrode boasts optimal sulfur utilization, elevated specific capacity, enhanced rate capabilities at intensified C rates, and steadfast cycling stability that underscore its vast commercial promise.

• Information Systems Review
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• v.19 no.1
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• pp.49-74
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• 2017

The development of smart devices has affected employees' working environments and their lives. However, using smart devices is causing employees to experience technostress. This study aims to investigate the effects of technostress in using smart devices on usage intention in an organization. Moreover, the study investigates the effect of employees' stress-coping methods on the intention to use smart devices. This study posits familiarity, use innovativeness, role ambiguity, system vulnerability, technological limitation, and ubiquity as the antecedents of technostress. Data collected from 317 users who have experience in using smart devices in organizations are empirically tested against a research model using the PLS graph. Analysis results show that role ambiguity, system vulnerability, and technological limitation significantly influence technostress. Moreover, users take up emotion-focused coping behaviors because of technostress. Emotion-focused coping behaviors affect usage intention in organizations. However, technostress and problem-focused coping behaviors do not directly affect usage intention in organizations.

• Korean Journal of Environmental Agriculture
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• v.22 no.1
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• pp.65-69
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• 2003

The adsorption characteristics of [$^{14}C$] mefenacet were investigated with six types of soil collected from different locations. The equilibrium time for adsorption was five hours. The adsorption coefficient(Kf) of Namwon series (volcanic ash soil) showed the highest value of 89.2 while Daejeon series (loamy sand) showed the lowest value of 2.37. The Kf values decreased in order of silty clay loam > silty loam > loamy sand > sandy loam, and the effect of soil properties on the adsorption of mefenacet in soil increased in order of clay mineral < CEC < organic matter. No significant effect was observed by the change of soil pH. The ground water ubiquity scores (GUS index) were $1.20{\sim}1.77$ in three types of soil while $1.81{\sim}2.42$ in the others, indicating that the former group belonged to nonleachers and the latter group to the transitional. Mefenacet in the test soil series seemed to have low possibility of contaminating ground water.

• Journal of Korea Multimedia Society
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• v.15 no.2
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• pp.215-225
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• 2012

In multimedia database, a multidimensional space-based indexing has been used to increase search efficiency. However, this method is inefficient in terms of ubiquity because it uses Euclidean distance as a scale of distance calculation. On the contrary, a metric space-based indexing method, in which metric axiom is prerequisite is widely available because a metric scale other than Euclidean distance could be used. This paper is attempted to propose a way of improving VP-tree, one of the metric space indexing methods. The VP-tree calculates the distance with an object which is ultimately linked to the a leaf node depending on the node fit for the search range from a root node and examines if it is appropriate with the search range. Because search speed decreases as the number of distance calculations at the leaf node increases, however, this paper has proposed a method which uses the latest interface on query object as the base point of trigonometric inequality for improvement after focusing on the trigonometric inequality-based range compression method in a leaf node. This improvement method would be able to narrow the search range and reduce the number of distance calculations. According to a system performance test using 10,000 video data, the new method reduced search time for similar videos by 5-12%, compared to a conventional method.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.46-53
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• 2004

Adsorption and leaching characteristics of hexaconazole were investigated to estimate the mobility potential of the compound in the soil environment. As well fitted to Freundlich adsorption isotherm, adsorptivity of hexaconazole, ranged 10.56-18.01 of Kf values, seemed high enough to be immobile in soil. This chemical leached more faster from fresh soil with rice plants. Most of $^{14}C$ (86-99% of originally applied $^{14}C$) was distributed within 5 cm soil depth from surface. Considering Koc values of 1,400-1,552 and Groundwater Ubiquity Score (GUS) indices of 1.25-1.35 as well as results from leaching experiment with soil column, hexaconazole falls into the category of improbable leacher, suggesting little mobility in soil.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.58-63
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• 2006

In order to elucidate the adsorption and leaching characteristics of the insecticide imidacloprid in two types of paddy soils near Suwon, this experiment was carried out with $[^{14}C]$imidacloprid as a radiotracer. In an adsorption study conducted using $[^{14}C]$imidacloprid in 2 test soils, the adsorption coefficient was higher in soil A $(K_f\;2.6)$ than that in soil B $(K_f\;1.7)$. As calculated from Freundlich constant, distribution coefficients and half lives in soils, GUS indices showed low leachabilities of imidacloprid treated on the paddy soils into the groundwater. The amount of imidacloprid leached from the soil columns during the 4 weeks of leaching was less than 2% of the originally treated $^{14}C$. In the leaching test the amounts of $^{14}C$ activities distributed in the soil layer of 0-10 cm were more than 80% of the originally tented $^{14}C$ and those in rice plants were less than 3% of the originally treated $^{14}C$, suggesting that imidacloprid has very low teachability and bioavailability.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.39-50
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• 2017

This study examined what leads to smartphone addiction by looking into personal, environmental, and smartphone characteristics, to identify their influences on the degree of addiction and changes in daily life. Therefore, surveys were conducted on college undergraduates, who get easily addicted to smartphones The study hypotheses were evaluated through a structural equation model on a total of 370 collected survey questionnaires Findings revealed: first, with reference to personal characteristics, the more competent and highly related one is, the more negatively influenced one is in getting addicted to smartphones. Second, as for environmental characteristics, the bigger the social impact is, the more positively influenced one is on smartphone addiction. Third, among the characteristics of a smartphone, the ubiquity showed a positive influence on smartphone addiction. Lastly, the degree to which one is addicted to a smartphone has(either positive or negative) on the changes in one's daily life. These results are not intended to blindly inhibit smartphone use by highlighting the negative aspects of smartphones, but are expected to serve as basic data to develop a preventative and remedial program based on the degree of smartphone addiction.

• The Journal of Information Systems
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• v.26 no.4
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• pp.247-284
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• 2017

Purpose The first purpose of this study is to investigate factors that are likely to influence user's intention to adopt third-party mobile payment platform. A comprehensive study about mobile payment services have used various variables to explain user's use intention based on the theory of reasoned action (TRA) or the theory of planned behavior (TPB). Variables such as simplicity, security, costs, relative advantage, individual mobility, subjective norm, trust, satisfaction, attitude towards use, perceived usefulness, perceived ease of use and so on. Among these factors, we expect to find out the most influential factors effecting user's use intention of the third-party mobile payment services. Second, we also examine whether the most influential factors have the same influence to different third-party mobile payment services by conducting comparative study of Alipay and WeChat Pay. Design/methodology/approach Empirical data for this study were collected from Chinese who has the experience using or have used Alipay or WeChat Pay. Participants needed to be familiar with Alipay or WeChat Pay because such users may be more aware of both the advantages and disadvantages of Alipay and WeChat Pay. We conduct a pilot test using Smart PLS 2.0, which includes 50 Alipay users and 82 WeChat Pay users. The result indicates that all the measurement fit for the context. And then 980 questionnaires were mainly sent out to the college students and the e-mails users randomly. To encourage participation, we give the participants a small gift as a present. Finally, we received a total of 683 replied. Data from respondents who gave incomplete or invalid answers were excluded to assure the validity of the constructs. 79 questionnaires were rejected, finally the valid data are 604 (with 372 Alipay users and 232 WeChat Pay users). Findings The results suggest that users' intention is determined by their trust on third-party mobile payment service and perceived usefulness of use. Comparative study results also indicated that the factors have different influence on Alipay group and WeChat Pay group, which offers a new aspect for academic field, and provides useful information to mobile payment service providers in China.

• Journal of Wetlands Research
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• v.22 no.2
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• pp.153-160
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• 2020

Most studies defined microplastic (MP) as plastic particles less than 5 mm. The ubiquity of MP is raising awareness due to its potential risk to humans and the environment. MP can cause harmful effects to humans and living organisms. This paper review aimed to provide a better understanding of the sources, pathways, and impacts of MP in the environment. MP can be classified as primary and secondary in nature. Moreover, microplastic can also be classified as based on its physical and chemical characteristics. Stormwater and wastewater are important pathways of introducing MP in large water bodies. As compared to stormwater, the concentrations of MP in wastewater were relatively lower since wastewater treatment processes can contribute to the removal of MP. In terms of polymer distribution, wastewater contains a wider array of polymer varieties than stormwater runoff. The most common types of polymer found in wastewater and stormwater runoff were polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE) and polyethylene terephthalate (PET). The continuous discharge and the increasing number of MP in the environment can pose greater hazards and harmful effects on humans and other living organisms. Despite the growing number of publications in relation to MP, further studies are needed to define concrete regulations and management strategies for mitigating the detrimental effects of MP in the environment.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.137-144
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• 2012

In order to monitor the pesticide residues in rice paddy soils and paddy waters in Korea and evaluate leachabilities to groundwater of the pesticides detected, paddy soils and paddy waters were collected twice from 40 sites of rice growing paddy fields in July and August in 2011, respectively. Pesticide residues in the samples were analyzed by multi-residue method with GC and HPLC. Five pesticides, such as butachlor, cypermethrin, iprobenfos, oxadiazon, and pendimethalin were detected from thirteen paddy soils and detection rate was about 16.3%, while no pesticide was detected in paddy water. As a results of the estimation of leachabilities for the pesticides detected using GUS (groundwater ubiquity score), their GUSs were less than 1.3, representing they have no potentials to leach into groundwater.