• Korean Journal of Mineralogy and Petrology
• /
• v.34 no.2
• /
• pp.95-106
• /
• 2021

The SO₄ in the jarosite structure can be substituted by other oxyanions, and therefore, the transition of jarosite to goethite plays a very important role in controlling the behavior of oxyanions. In this study, the phase change according to the species of the oxyanion in jarosite and the related behavior of the oxyanion was studied by mineralogical and geochemical methods when jarosite, which is coprecipitated with various oxynions, undergoes a phase change by a reductive dissolution. Jarosite substituted by five oxyanions by 5 mol% was used in this study. The mineral phase change induced by reductive dissolution using ammonium oxalate was investigated, and the order of phase transition rate of jarosite to goethite was MoO₄-jarosite ≥ SeO₄-jarosite ≥ CrO₄-jarosite > pure jarosite > SeO₃-jarosite > AsO₄-jarosite, showing that the transition rates vary depending on the substituted oxyanion. The resultant concentration of the leached Fe was slightly different depending on the type of oxyanion and time but did not show a noticeable difference. The concentration of each oxyanion leached according to the change of the mineral phase showed that the order of concentration of oxyanions was Mo > Se(SeO₃) > As > Se(SeO₄) > Cr in general, and showed a slight increase with time. This trend was related to the species of oxyanions rather than mineral phase change. The results of this study showed that the phase transition of jarosite to goethite was affected by the species of oxyanions, but this tendency did not affect the concentrations leached oxyanions.

• The Journal of the Korea Contents Association
• /
• v.20 no.4
• /
• pp.212-229
• /
• 2020

'Live + Sale' is actively promoted in China and 'Wang-Hong', also known as Chinese internet celebrities are dominating this format of marketing strategy recently. They introduce products to consumers through live broadcasts, promote online shopping, and frequently evoke impulsive buying. Under this context, it is worth focusing on what factors influence impulse buying during Wang-Hong's live broadcast. This study investigated the impact of Wang-Hong characteristics on impulse buying behavior when watching live sales. Also, the mediating role of flow experience and viewing satisfaction was explored. Furthermore, we expected that the different live broadcast circumstances could have a different impact on flow experience, viewing satisfaction, and impulse purchase. A total of 242 Chinese women who have experience of viewing live sales were recruited through a Chinese research platform. The results revealed that Wang-Hong's trustworthiness and attractiveness positively affected the viewer's impulse buying directly, and indirectly through flow experience and viewing satisfaction, whereas expertise did not have any impact on impulse purchase. However, there were no significant differences between the two live broadcast circumstances. This research can enhance understanding of the impulse buying process during Wang-Hong's live sale and help brands come up with effective influencer marketing strategies using live sales.

• Journal of the Korea Convergence Society
• /
• v.11 no.8
• /
• pp.341-350
• /
• 2020

This study was conducted to investigate the relationship between authentic leadership of nursing managers and team creativity: the mediation role of positive psychological capital. The study participants were 124 staff nurses. The measurements included authentic leadership, psychological capital and team creativity. Data were analyzed using Pearson's correlation coefficient and Baron and Kenny's three-level hierarchical regression analysis with SPSS 25.0 to identify correlation among variables and mediating effect of positive psychological capital. The research results indicated that the higher the authentic leadership, the higher the team's creativity and the higher the nurse's positive psychological capital and confirmed that positive psychological capital has a partial mediating effect in the relationship between authentic leadership and team creativity. The findings suggest that in order to improve the team creativity of staff nurses, converged organizational behavior management strategies are needed to improve the authentic leadership of managers perceived by staff nurses and the positive psychological capital of staff nurses.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.1
• /
• pp.158-167
• /
• 2018

The role of S/W in weapon systems has been developed with various functions and complex structures. As the weapon system S/W is directly related to quick and accurate decision making of users, more accurate evaluation is required during the training. However, situation awareness of weapon system S/W users has only been assessed qualitatively such as by simple test or qualitative judgement. Therefore, this study suggests the 'Cognition Ratio' concept which represents the quantitative of users by combining ACT-R cognitive architecture to SA (Situation Awareness) and Fitts' Law based on the theory of cognitive engineering. The cognition ratio is a ratio of cognition among the whole cognitive behavior process including perception and psychomotor. Moreover, this study provides a systematic assessment process of situation awareness that will be applicable to various weapon system S/W for effective assessment.

• Journal of the Korean Electrochemical Society
• /
• v.19 no.1
• /
• pp.1-8
• /
• 2016

Capacity of layered lithium nickel-cobalt-manganese oxide ($LiNi_{1-x-y}Co_xMn_yO_2$) cathode material can increase by raising the charge cut-off voltage above 4.3 V vs. $Li/Li^+$, but it is limited due to anodic instability of conventional electrolyte. We have been screening and evaluating various sulfone-based compounds of dimethyl sulfone (DMS), diethyl sulfone (DES), ethyl methyl sulfone (EMS) as electrolyte additives for high-voltage applications. Here we report improved cycling performance of $LiNi_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode by the use of dimethyl sulfone (DMS) additive under an aggressive charge condition of 4.6 V, compared to that in conventional electrolyte, and cathode-electrolyte interfacial reaction behavior. The cathode with DMS delivered discharge capacities of $198-173mAhg^{-1}$ over 50 cycles and capacity retention of 84%. Surface analysis results indicate that DMS induces to form a surface protective film at the cathode and inhibit metal-dissolution, which is correlated to improved high-voltage cycling performance.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.11 no.3
• /
• pp.75-84
• /
• 1991

When we construct the earth structures such as embankments, on soft ground which are consisted of thick marine silty clay, the foundations deform due to consolidation and creep. For the stabilization of the earth structures constructed on soft foundations, we usually uses the mattress and they play an important role in increasing an ultimate bearing capacity by the dispersion of load of embankment. The purpose of this paper was to predict rationally a long term deformation of earth structures and to contribute to embankment design and maintenance. We determined a rheological model of marine clay from experimental data, and developed a computer program using the chosen model and found out the long term behavior of embankment. The results of this paper are as follows: 1. The developed program can analyze simultaneously consolidation and creep. 2. From the results of creep test, the rheological model of marine silty clay can be represented by the Vyalov model. 3. The displacement of embankment on reinforced foundation were smaller than those of the unreinforced foundation in showing the effects of geotextiles on foundation deformations.

• Journal of Oral Medicine and Pain
• /
• v.38 no.1
• /
• pp.69-76
• /
• 2013

Aim : The purpose of this study was to investigate the hypothesis that treatment with self-checking behavior management program was valuable in the management of temporomandibular disorders compared with a existing method treatment group. Methods : All participants who are diagnosed with temporomandibular disorders were treated with medication and physical therapy. They came into the clinic at intervals of two weeks, three times. The signs and symptoms were assessed investigating Pain NRS(Numerical Rating Scale), MCO(Maximum comfortable opening), Noise NRS, LOM(Limitation of Mouth opening) NRS at every visit. Experimental group received instructions repeatedly by using self evaluation questionnaire. Control group was educated once at the beginning of treatment. The difference Pain NRS, MCO, Noise NRS, LOM NRS between first and second visits, first and third visits were estimated.. Result :Experimental group showed greater improvement on MCO difference after stopping medication(p=0.001). This improvements were prominent in the male(p=0.001) and the first or second decade of the patients(p=0.004). Conclusion : The present study showed that there was better result when educating repeatedly with using self evaluation questionnaire than educating once at the beginning of the treatment.

• Polymer(Korea)
• /
• v.38 no.3
• /
• pp.364-370
• /
• 2014

The retinal pigment epithelium (RPE) plays an important role in maintaining a healthy retina and the degeneration of RPE caused a number of retinal diseases. The transplantation of RPE has recently become a possible therapeutic modality for retinal degeneration. To transplant RPE cells securely, substrates are essential, and then as a substrate, we fabricated films using silk that has unique mechanical properties and biocompatibility. After the FTIR spectra, contact angle and biodegradation of silk films were confirmed, RPE cells were seeded and the influence of RPE cells on silk films was examined. We measured the cell adhesion, cell viability, morphology and specific mRNA expression by MTT assay, SEM, immunofluorescence and RT-PCR. In this study, we confirmed that attachment, proliferation and phenotype maintenance of RPE cells cultured on silk films were great, and thereby we were able to confirm the potential applications of silk films as tissue engineering carrier for regeneration of retina.

• Journal of the Korea Convergence Society
• /
• v.8 no.9
• /
• pp.301-309
• /
• 2017

This study analyzed the effect of cooperation activities among SMEs. In order to study empirical analysis, we classified the types of cooperation into four dimensions: technology cooperation, human resource cooperation, sales cooperation and financial cooperation. Review the role of the collaborative philosophy as a predictor. This study also analyzed the relationship between cooperation philosophy, cooperation activities and performance. The results of this study are as follows: First, the result of path analysis between cooperation philosophy and cooperation activities shows that cooperation philosophy has an important influence on technical cooperation, human resource cooperation, sales cooperation and financial cooperation. Second, the results of the relationship between cooperation activities and achievements, technical cooperation, human resource cooperation, and sales cooperation have an important influence on cooperation performance. The meaning of this study is as follows. Analyze empirical tests using the PSBP model from a partnership perspective. We are trying to verify the relationship with SMEs. Therefore, we can suggest a beneficial implication to explain the importance of cooperation activities between SMEs. Also, SME business units have a problem with technical information leakage when they form partnerships, but in order to overcome this problem, we can use cooperative philosophies and avoid negative views.

• Information Systems Review
• /
• v.17 no.3
• /
• pp.77-94
• /
• 2015

As Internet has become a popular media for sharing information, users create and share tremendous volume of information including large amount of personal information in cyberspace. Sharing private information online can enhance strength of social relationship but it could also bring negative consequences like information privacy invasion. Although many companies and governments address the importance of information privacy online, there are countless cases of crimes and hackings relating personal information online world wide. Since there are some researches investigating the role of governments and organizations on online privacy domain but there is little research regarding users' privacy protection behaviors. This study investigates relationship between Internet users' information privacy protection behavior and environmental factors. Especially, this study focuses on users' behaviors regarding information privacy protection technology adoption. According to our research results, users' online privacy protective behaviors positively affected by governmental regulations expressed as an information privacy protection law. In addition, if user is allowed to use anonymity when he or she uses online services, they have more tendencies to adopt privacy protection technologies. The detailed research findings and contribution are discussed as well.