• The Journal of Society for e-Business Studies
• /
• v.20 no.1
• /
• pp.217-241
• /
• 2015

One of the challenges in online community management is what level of perceived anonymity can be granted to encourage active participation from members while discouraging unhealthy activities. Few studies developed a scheme of anonymity and investigated how different levels of anonymity influence community activities. This study develops a classification scheme of anonymity encompassing the following three different levels : (1) real name(no anonymity), (2) nickname (partial anonymity), and (3) random assignment of a temporal ID (complete anonymity). Then, it examines how different levels of anonymity influence trust and perceived risk, which in turn affect virtual team performance. A series of laboratory experiments were performed, manipulating the levels of anonymity, in the context of well-structured communities that allow prior interactions among community members. The data was collected from 364 laboratory participants and analyzed using ANOVA and PLS. The results indicate that the difference of anonymity between (2) and (3) had not be significant and the only (1) could not guarantee the anonymity. The impact of anonymity on trust and perceived risk could not be significant in this situation. These findings could contribute to make more beneficial member identification strategies in online community practice.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.417-417
• /
• 2016

Global environmental deterioration has become more serious year by year and thus scientific interests in the renewable energy as environmental technology and replacement of fossil fuels have grown exponentially. Photoelectrochemical (PEC) cell consisting of semiconductor photoelectrodes that can harvest light and use this energy directly to split water, also known as photoelectrolysis or solar water splitting, is a promising renewable energy technology to produce hydrogen for uses in the future hydrogen economy. A major advantage of PEC systems is that they involve relatively simple processes steps as compared to many other H2 production systems. Until now, a number of materials including TiO2, WO3, Fe2O3, and BiVO4 were exploited as the photoelectrode. However, the PEC performance of these single absorber materials is limited due to their large charge recombinations in bulk, interface and surface, leading low charge separation/transport efficiencies. Recently, coupling of two materials, e.g., BiVO4/WO3, Fe2O3/WO3 and CuWO4/WO3, to form a type II heterojunction has been demonstrated to be a viable means to improve the PEC performance by enhancing the charge separation and transport efficiencies. In this study, we have prepared a triple-layer heterojunction BiVO4/WO3/SnO2 photoelectrode that shows a comparable PEC performance with previously reported best-performing nanostructured BiVO4/WO3 heterojunction photoelectrode via a facile solution method. Interestingly, we found that the incorporation of SnO2 nanoparticles layer in between WO3 and FTO largely promotes electron transport and thus minimizes interfacial recombination. The impact of the SnO2 interfacial layer was investigated in detail by TEM, hall measurement and electrochemical impedance spectroscopy (EIS) techniques. In addition, our planar-structured triple-layer photoelectrode shows a relatively high transmittance due to its low thickness (~300 nm), which benefits to couple with a solar cell to form a tandem PEC device. The overall PEC performance, especially the photocurrent onset potential (Vonset), were further improved by a reactive-ion etching (RIE) surface etching and electrocatalyst (CoOx) deposition.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.65-65
• /
• 2015

In this talk, I will introduce two topics. The first topic is the polymer light emitting diodes (PLEDs) using graphene oxide quantum dots as emissive center. More specifically, the energy transfer mechanism as well as the origin of white electroluminescence in the PLED were investigated. The second topic is the facile synthesis of eco-friendly III-V colloidal quantum dots and their application to light emitting diodes. Polymer (organic) light emitting diodes (PLEDs) using quantum dots (QDs) as emissive materials have received much attention as promising components for next-generation displays. Despite their outstanding properties, toxic and hazardous nature of QDs is a serious impediment to their use in future eco-friendly opto-electronic device applications. Owing to the desires to develop new types of nanomaterial without health and environmental effects but with strong opto-electrical properties similar to QDs, graphene quantum dots (GQDs) have attracted great interest as promising luminophores. However, the origin of electroluminescence (EL) from GQDs incorporated PLEDs is unclear. Herein, we synthesized graphene oxide quantum dots (GOQDs) using a modified hydrothermal deoxidization method and characterized the PLED performance using GOQDs blended poly(N-vinyl carbazole) (PVK) as emissive layer. Simple device structure was used to reveal the origin of EL by excluding the contribution of and contamination from other layers. The energy transfer and interaction between the PVK host and GOQDs guest were investigated using steady-state PL, time-correlated single photon counting (TCSPC) and density functional theory (DFT) calculations. Experiments revealed that white EL emission from the PLED originated from the hybridized GOQD-PVK complex emission with the contributions from the individual GOQDs and PVK emissions. (Sci Rep., 5, 11032, 2015). New III-V colloidal quantum dots (CQDs) were synthesized using the hot-injection method and the QD-light emitting diodes (QLEDs) using these CQDs as emissive layer were demonstrated for the first time. The band gaps of the III-V CQDs were varied by varying the metal fraction and by particle size control. The X-ray absorption fine structure (XAFS) results show that the crystal states of the III-V CQDs consist of multi-phase states; multi-peak photoluminescence (PL) resulted from these multi-phase states. Inverted structured QLED shows green EL emission and a maximum luminance of ~45 cd/m2. This result shows that III-V CQDs can be a good substitute for conventional cadmium-containing CQDs in various opto-electronic applications, e.g., eco-friendly displays. (Un-published results).

• Korean Journal of Health Education and Promotion
• /
• v.24 no.3
• /
• pp.61-71
• /
• 2007

Objectives: The research was conducted to evaluate the socio-demographic, life style and work related factors of stress and fatigue, and correlation between them in the white collar workers. Methods: This study was targeted on white collar workers of medium-sized company in Kimhae city including 249 people; 167 of males, 82 of females. The data was collected by structured questionnaires and analyzed using t-test, ANOVA, Pearson correlation and stepwise multiple regression with SPSS 12.0. Result: Both stress and fatigue levels were higher for female of gender, 20s of age, single of marital status in socio-demographic factors. The stress level was higher for current smokers and lower frequency of regular exercise per week, and both stress and fatigue levels were higher for unsatisfied sleeping in lifestyle factors. The stress level was lower for 5-day workweek system and experience of downsizing, and both stress and fatigue levels were higher far lower period of employment in work related factors. The correlation coefficient(r) between stress and fatigue level was 0.578, which was highly statistically significant. According to stepwise multiple regression analysis, factors affecting stress were unsatisfied sleeping, female and lower frequency of regular exercise per week, and those affecting fatigue were younger age and unsatisfied sleeping. Conclusion: This study provided strong support for associations between stress and fatigue, and we suggest that modifiable factors such as regular exercise and satisfied sleeping would be important for white collar workers to reduce their stress and fatigue.

• Journal of Fisheries and Marine Sciences Education
• /
• v.25 no.4
• /
• pp.898-914
• /
• 2013

The fusion type human resources, it is a new human resources to scientific and technical information society of the future demands, and means to enjoy life with a creativity and expertise of fusion of various fields, to communicate in consideration of others. Fusion human resource education(STEAM), of "human resources to practice respect and compassion", "human resources equipped with communication skills", "human resources to pursue creativity and innovation" "human resources to understand the knowledge of the fusion to take advantage" in training I have presented to the area of core competence of the 4C 'Creativity"," Communication","Convergence', 'Caring'. In this study, the area of c ore competency for each element by elementary, middle, and high schools around the analysis of the target can be made by each school level to develop a practical program in the sense of basic research is to conduct. The findings are as follows: First, Area of Creativity, communication area, the contents fusion region, as well as care areas, to the detailed item capacity, the design of the class that contains the entire area should be performed. Second, Elementary and secondary school level analysis, design of the class containing the entire region up to capacity detail is required. High school was required study of school full of normal. Third, In general, for STEAM class environment and teaching model was developed by applying operations. Research and methods of teaching a wider variety of form was required. Later in this study is to develop programs and organize. and It intends to become the base to be able to interest and interest in science education by structured around the status of problems that can be found in the life of around themes STEAM.

• The KIPS Transactions:PartB
• /
• v.14B no.6
• /
• pp.453-460
• /
• 2007

In this paper, we present a method to extract the text lines in poorly structured documents. The text lines may have different orientations, considerably curved shapes, and there are possibly a few wide inter-word gaps in a text line. Those text lines can be found in posters, blocks of addresses, artistic documents. Our method based on the traditional perceptual grouping but we develop novel solutions to overcome the problems of insufficient seed points and vaned orientations un a single line. In this paper, we assume that text lines contained tone connected components, in which each connected components is a set of black pixels within a letter, or some touched letters. In our scheme, the connected components closer than an iteratively incremented threshold will make together a chain. Elongate chains are identified as the seed chains of lines. Then the seed chains are extended to the left and the right regarding the local orientations. The local orientations will be reevaluated at each side of the chains when it is extended. By this process, all text lines are finally constructed. The proposed method is good for extraction of the considerably curved text lines from logos and slogans in our experiment; 98% and 94% for the straight-line extraction and the curved-line extraction, respectively.

• Journal of the Economic Geographical Society of Korea
• /
• v.24 no.1
• /
• pp.52-75
• /
• 2021

The current Korean labour movement is at an impasse that is partly sustained by the idea of "strong" transnational corporations (TNCs) versus "weak" labour, and this perception is based on the "global-local dichotomy," wherein TNCs are depicted as abstract and structured entities operating at the global scale and workers are represented as having a concrete and weak presence within the local sphere. As an alternative perspective to break this "global" capital vs. "local" labour dichotomy, I focus on labour geography, which assumes that labour is not simply a factor of production but a sentient spatial actor that (un-)intentionally produces the landscape of capitalism. Borrowing insights from the multi-scalar perspective, this paper aims to understand the actual methods in which workers utilize spatial strategies through an empirical case study of the Nestlé Korea labour union strike in 2003. Based on this case study, this paper claims that workers are both capable of employing coordinated multi-scalar practices and can be more influential to the economic geographies of TNCs. Additionally, it suggests that workers' scalar practices are actually more complicated and multi-directional as a result of their complex and dynamic interactions with political, economic and cultural forces and actors at diverse geographical scales.

• Journal of Digital Convergence
• /
• v.17 no.3
• /
• pp.291-304
• /
• 2019

The purpose of this study was to identify factors influencing family caregivers' reaction of persons with cancer. The study participants were 130 cancer patients and their family caregivers. Data on participant characteristics, caregiver reaction, perceived social support, and cancer related health literacy were collected from July 17 to November 7, 2018 using a structured questionnaire. Data were analyzed with the SPSS/WIN 23.0 program for descriptive statistics, using independent t-test, one-way analysis of variance, Pearson's correlation coefficient and enter multiple regression analysis. The determining factors affecting caregivers' reaction were in case of spouse of patient(${\beta}=.252$, p=.002), subjective health status(${\beta}=-.207$ p=.012), and health literacy (self-care, patient's needs and preference) (${\beta}=-.411$, p<.001; ${\beta}=.247$, p=.037 respectively), and their explanation power was about 37.9%. This finding underscores the need for developing and application of the individualized education program with health literacy improvement strategies for family caregivers of cancer patients.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.5
• /
• pp.780-790
• /
• 2022

Quantitative risk levels must be presented by analyzing the causes and consequences of accidents and predicting the occurrence patterns of the accidents. For the analysis of marine accidents related to vessel traffic, research on the traffic such as collision risk analysis and navigational path finding has been mainly conducted. The analysis of the occurrence pattern of marine accidents has been presented according to the traditional statistical analysis. This study intends to present a marine accident prediction model using the statistics on marine accidents related to vessel traffic. Statistical data from 1998 to 2021, which can be accumulated by month and hourly data among the Korean domestic marine accidents, were converted into structured time series data. The predictive model was built using a long short-term memory network, which is a representative artificial intelligence model. As a result of verifying the performance of the proposed model through the validation data, the RMSEs were noted to be 52.5471 and 126.5893 in the initial neural network model, and as a result of the updated model with observed datasets, the RMSEs were improved to 31.3680 and 36.3967, respectively. Based on the proposed model, the occurrence pattern of marine accidents could be predicted by learning the features of various marine accidents. In further research, a quantitative presentation of the risk of marine accidents and the development of region-based hazard maps are required.

• Sleep Medicine and Psychophysiology
• /
• v.16 no.2
• /
• pp.65-73
• /
• 2009

Objectives: The purpose of this study was to assess the clinical and polysomnographic characteristics of Korean patients with obstructive sleep apnea syndrome (OSAS), especially in relation to differences due to age and gender. Methods: All subjects were consecutive patients who were proven to have OSAS with nocturnal polysomnography. They were interviewed with a structured interview format including sociodemographic information, past medical history, medication, and sleep-related history. Simultaneously, they were also given Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) to answer in order to check subjective sleep quality and subjective sleepiness. Results: Mean age of the 308 subjects was $49.5{\pm}$13.3 years, with 77.6% of the subjects being males and 22.4% of the subjects being females. The aging effects on the sleep architecture in Korean OSAS corresponded with normal aging, but with the effect of OSAS itself superimposed, the extent of aging effects was more marked than that of normal aging. The severity of Korean patients of OSAS was not correlated with age. When divided into age subgroups, significant correlation was found between RDI and BMI in patients of each subgroup of those in the 4th to 7th decades. The oldest subgroup (>70 years) described their subjective sleep quality as poorer than any other age subgroups, despite of less subjective drowsiness. The severity of OSAS and the change of sleep architecture of male subjects turned out to be severer than those of female ones. The female/male ratio of the subjects tended to increase with aging. Conclusions: The aging effect on the sleep architecture in Korean OSAS seems to be a mixture of the changes by normal aging and sleep disorder per se. The severity of OSAS was not correlated with age, but highly correlated with BMI. The severity of OSAS and the change of sleep architecture of male patients were severer than those of female ones.