• The Journal of Society for e-Business Studies
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• v.25 no.4
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• pp.61-75
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• 2020

The scope of data for understanding or predicting stock prices has been continuously widened from traditional structured format data to unstructured data. This study investigates whether commentary data collected from SNS may affect future stock prices. From "Stock Discussion Room" in Naver, we collect 20 stocks' commentary data for six months, and test whether this data have prediction power with respect to one-hour ahead price direction and price range. Deep neural network such as LSTM and CNN methods are employed to model the predictive relationship. Among the 20 stocks, we find that future price direction can be predicted with higher than the accuracy of 50% in 13 stocks. Also, the future price range can be predicted with higher than the accuracy of 50% in 16 stocks. This study validate that the investors' sentiment reflected in SNS community such as Naver's "Stock Discussion Room" may affect the demand and supply of stocks, thus driving the stock prices.

• The Research Journal of the Costume Culture
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• v.18 no.5
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• pp.977-990
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• 2010

Today, as individuals show their social identities and reflect their being as the members of society with a culture, an art style and communication function are stood out in fashion photographs. Accordingly, the meanings of images into text are expanded in its interpretative width through the acceptor's various terms. This researcher looked into four theories of both positions on the textuality of language and image, and considered the point of discussion on image of each theory through modern fashion photographs. First, the theory which divides language and image as auditory and visual recognitions in the textuality of language and image is limited from the view it focuses on only one side without considering the ambivalent elements of each field. For the textuality in modern fashion photographs, the observer attempts to turn it into text to give meaning to it as the recognition through five senses conforming to the acceptor's condition. Second, the theory dividing language and image into the text of time properties and spacial properties has limitation in the text, for acceptor's experience of the object appears as the structured form in time and space rather than being defined as two things like time and space. Third, the theory classifying the language and image text into conventional taste and natural taste has limitation from the view that image text is hardly an object of consistent classification in ease of recognition by the code accepted in society. Thus, this can't be fundamental approach for the understanding of the text of decoding trend represented in modern fashion photographs. Fourth, accordingly, this researcher focussed on contextual and arbitrary text of fashion photographs through the theory of Nelson Goodman which discusses image text through the differences in textuality. Basic mechanism of perceiving and recognizing and distinguish image is closely related to habit and custom like language. So, each acceptor perceives the image as a text through arbitrary interpretation obtained by individual, empirical, historical, and educational viewpoints. The textuality of modern fashion photographs aims to widen the range of diverse knowledge and understanding, transcending the regulations of simple function of existing fashion photographs. Consequently, this researcher puts forward the opinion of consistent and diverse follow-up studies on instilling meaning into fashion photographs for the understanding de-regulatory and de-constructive through various senses by avoiding only one sense-dependent fixed and regulatory properties of it.

• Safety and Health at Work
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• v.11 no.1
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• pp.118-124
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• 2020

Background: The poultry industry in Pakistan has flourished since the 1960s; however, there are scarce data regarding the impact of occupational exposure on the pulmonary health of farm workers in terms of years working in the industry. The objective of the present study was to assess the effect of poultry environment on the health of occupationally exposed poultry farmers in countries of warm climatic regions, such as Pakistan. This study will also show the effect of exposure to poultry facilities on the health of poultry farmers in the context of low-income countries with a relatively inadequate occupational exposure risk management. Materials and methods: The lung function capacity of 79 poultry workers was measured using a spirometer. Along with spirometry, a structured questionnaire was also administrated to obtain information about age, height, weight, smokers/nonsmokers, years of working experience, and pulmonary health of farm workers. The workers who were directly involved in the care and handling of birds in these intensive facilities were considered and divided into four groups based on their years of working experience: Group I (3-10 months), Group II (1-5 years), Group III (6-10 years), and Group IV (more than 11 years). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio were considered to identify lung function abnormalities. Statistical analysis was carried out using independent sample t test, Chi-square test, Pearson's correlation, and linear regression. Results: Based on the performed spirometry, 68 (86 %) of workers were found normal and healthy, whereas 11 (14 %) had a mild obstruction. Of the 11 workers with mild obstruction, the highest number with respect to the total was in Group IV (more than 11 years of working experience) followed by Group III and Group II. Most of the workers were found healthy, which seems to be because of the healthy survivor effect. For the independent sample t test, a significant difference was noticed between healthy and nonhealthy farmers, whereas Chi-square test showed a significant association with height, drugs, and working experience. Linear regression that was stratified by respiratory symptoms showed for workers with symptoms, regression models for all spirometric parameters (FVC, FEV1, and FEV1/FVC) have better predictive power or R square value than those of workers without symptoms. Conclusion: These findings suggest that lung function capacity was directly related to years of working experience. With increasing number of working years, symptoms of various respiratory problems enhanced in the poultry workers. It should be noted that most of the poultry workers were healthy and young, the rationale being that there is a high turnover rate in this profession. The mobility in this job and our finding of 86% of the healthy workers in the present study also proposed healthy worker survivor effect.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1365-1372
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• 2018

The purpose of this study is to analyze the importance of the determinants of housing sales agency's role in the sale of apartment housing. For this purpose, a hierarchical decision model was constructed to understand the role and importance of the sales agency. The analytical variable items structured by the research model were set up through literature review, precedent research, and expert brainstorming. The questionnaire consisted of two comparisons for AHP analysis and the importance of absolute importance for fuzzy analysis. Afterwards, the work of correcting the importance was carried out. As a result of the analysis, it was found that the contractor prioritized the sale conditions and the sales agency had priority over the planning for the sale. As a result of analysis, planning of customer pre-sale counseling data, planning of client subscription and contract maximization plan, planning method of advertisement public media method were found to be the most important factors. The results of measurement of absolute importance(fuzzy) & relative importance(,AHP) showed similar tendency. Therefore, it can be seen that the timing of the model house operation is an important period in which the subscription rate depends on the role of the sales agency and the marketing strategy.

• Korean Journal of Acupuncture
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• v.35 no.3
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• pp.130-138
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• 2018

Objectives : The purpose of this study is to explore patients' perceptions that deserve attention when designing core questions for a clinical practice guideline of Korean medicine(KM) for degenerative lumbar spinal stenosis (LSS). Methods : Patients who had been admitted to Pusan National Korean Medicine Hospital from November 1, 2015 to October 31, 2016 were invited to the survey. Patients were eligible if they were both clinically and radiologically confirmed as degenerative LSS. The structured questionnaire was distributed by mail and outpatient visits. Questions included types of experienced Korean/Western medical interventions for LSS, their perceived effectiveness on symptoms, the necessity for studies of KM for degenerative LSS, the types of KM interventions to be investigated and the types of outcome measures after treatments. Data were descriptively analysed. Results : Twenty of thirty-one invited participants responded to the questionnaire. Acupuncture and herbal medicine were the most frequently used KM interventions. Eighteen respondents reported that KM treatments were helpful for their improvement. Sixteen patients who mentioned that research on KM is needed chose acupuncture as the top priority(88%) among KM interventions. The most important outcomes in the view of nineteen respondents included functional recovery (68%) and pain relief (53%). Thirteen respondents (65%) replied that both short-term and long-term outcome were important for them. Conclusions : Our findings may have limited validity due to the small number of respondents and the potential selection and information bias. Further qualitative studies and large-scale surveys to comprehensively identify patients' views are warranted.

• Communications of Mathematical Education
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• v.34 no.3
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• pp.215-234
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• 2020

With the advent of the AI, the need to use AI in the field of education is widely recognized. The purpose of this study is to shed light on how prospective mathematics teachers perceive the need for AI and the role of teachers in future mathematics education. As a result, with regard to teaching, prospective teachers recognized that the use of AI in school mathematics is a demand of a new era, that various types of lesson can be implemented, and that accurate knowledge and information can be delivered. On the other hand, they recognized that AI has limitations in having cognitive and emotional interactions with students. As for mathematics learning, the prospective teachers recognized that AI can provide individualized learning, be used for supplementary learning outside of school, and stimulate students' interest in learning. However, they also said that learning through AI could undermine students' ability to think on their own. With regard to assessment, the prospective teachers recognized that AI is objective, fair and can reduce teachers' workload, but they also said that AI has limitations in evaluating students' abilities in constructed-response items and in process-focused assessment. The roles of teachers that the prospective teachers think were to conduct a lesson, emotional interaction, unstructured assessment, and counseling, and those of AI were individualized learning, rote learning, structured assessment, and administrative works.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.588-588
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• 2013

Nanoscale noble-metals have attracted enormous attention from researchers in various fields of study because of their unusual optical properties as well as novel chemical properties. They have possible uses in diverse applications such as devices, transistors, optoelectronics, information storages, and energy converters. It is well-known that nanoparticles of noble-metals such as silver and gold show strong absorption bands in the visible region due to their surface-plasmon oscillation modes of conductive electrons. Silver nanocubes stand out from various types of Silver nanostructures (e.g., spheres, rods, bars, belts, and wires) due to their superior performance in a range of applications involvinglocalized surface plasmon resonance, surface-enhanced Raman scattering, and biosensing. In addition, extensive efforts have been devoted to the investigation of Gold-based nanocomposites to achieve high catalytic performances and utilization efficiencies. Furthermore, as the catalytic reactivity of Silver nanostructures depends highly on their morphology, hollow Gold nanoparticles having void interiors may offer additional catalytic advantages due to their increased surface areas. Especially, hollow nanospheres possess structurally tunable features such as shell thickness, interior cavity size, and chemical composition, leading to relatively high surface areas, low densities, and reduced costs compared with their solid counterparts. Thus, hollow-structured noblemetal nanoparticles can be applied to nanometer-sized chemical reactors, efficient catalysts, energy-storage media, and small containers to encapsulate multi-functional active materials. Silver nanocubes dispersed in water have been transformed into Ag@Au nanoboxes, which show highly enhanced catalytic properties, by adding $HAuCl_4$. By using this concept, $SiO_2$-coated Ag@Au nanoboxes have been synthesized via galvanic replacement of $SiO_2$-coated Ag nanocubes. They have lower catalytic ability but more stability than Ag@Au nanoboxes do. Thus, they could be recycled. $SiO_2$-coated Ag@Au nanoboxes have been found to catalyze the degradation of 4-nitrophenol efficiently in the presence of $NaBH_4$. By changing the amount of the added noble metal salt to control the molar ratio Au to Ag, we could tune the catalytic properties of the nanostructures in the reduction of the dyes. The catalytic ability of $SiO_2$-coated Ag@Au nanoboxes has been found to be much more efficient than $SiO_2$-coated Ag nanocubes. Catalytic performances were affected noteworthily by the metals, sizes, and shapes of noble-metal nanostructures.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.402-409
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• 2006

Although microorganisms are, in fact, the most diverse and abundant type of organism on Earth, the ecological functions of microbial populations remains poorly understood. A variety of bacteria including marine Vibrios encounter numerous ecological challenges, such as UV light, predation, competition, and seasonal variations in seawater including pH, salinity, nutrient levels, temperature and so forth. In order to survive and proliferate under variable conditions, they have to develop elaborate means of communication to meet the challenges to which they are exposed. In bacteria, a range of biological functions have recently been found to be regulated by a population density-dependent cell-cell signaling mechanism known as quorum-sensing (QS). In other words, bacterial cells sense population density by monitoring the presence of self-produced extracellular autoinducers (AI). N-acylhomoserine lactone (AHL)-dependent quorum-sensing was first discovered in two luminescent marine bacteria, Vibrio fischeri and Vibrio harveyi. The LuxI/R system of V. fischeriis the paradigm of Gram-negative quorum-sensing systems. At high population density, the accumulated signalstrigger the expression of target genes and thereby initiate a new set of biological activities. Several QS systems have been identified so far. Among them, an AHL-dependent QS system has been found to control biofilm formation in several bacterial species, including Pseudomonas aeruginosa, Aeromonas hydrophila, Burkholderia cepacia, and Serratia liquefaciens. Bacterial biofilm is a structured community of bacterial cells enclosed in a self-produced polymeric matrix that adheres to an inert or living surface. Extracellular signal molecules have been implicated in biofilm formation. Agrobacterium tumefaciens strain NT1(traR, tra::lacZ749) and Chromobacterium violaceum strain CV026 are used as biosensors to detect AHL signals. Quorum sensing in lactic acid bacteria involves peptides that are directly sensed by membrane-located histidine kinases, after which the signal is transmitted to an intracellular regulator. In the nisin autoregulation process in Lactococcus lactis, the NisK protein acts as the sensor for nisin, and NisR protein as the response regulator activatingthe transcription of target genes. For control over growth and survival in bacterial communities, various strategies need to be developed by which receptors of the signal molecules are interfered with or the synthesis and release of the molecules is controlled. However, much is still unknown about the metabolic processes involved in such signal transduction and whether or not various foods and food ingredients may affect communication between spoilage or pathogenic bacteria. In five to ten years, we will be able to discover new signal molecules, some of which may have applications in food preservation to inhibit the growth of pathogens on foods.

• Membrane Journal
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• v.28 no.5
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• pp.340-350
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• 2018

In the present study, crystallographically b- and c-axis oriented mordenite zeolite membranes were prepared and their pervaporative ethanol dehydration was investigated. The seed layer with a high coverage grew to be c-axis oriented dense layer, while the seed layer with a low coverage grew to be b-axis oriented layer. This phenomenon could be explained by the evolutionary selection growth mechanism. The b-axis grown membrane with 8-membered rings showed a high separation factor of above 1000 and a considerable total flux of around $0.2kg/m^2h$. The c-axis grown, columnar structured membrane with 8- and 12-membered rings showed a low separation factor of less than 200 and a relatively high total flux of around $0.25kg/m^2h$. The high performance of b-axis grown membrane was due to the relatively small opening of 8-membered rings. Water molecules can freely permeate through the openings, but ethanol molecules, difficultly. Therefore, in the present study, we introduced a new method to control crystallographic orientation of mordenite membrane by changing seeding amount of needle-like crystals, and elucidated that b-axis oriented mordenite membrane showed better performance than c-axis grown mordenite membrane.

• Journal of the Mineralogical Society of Korea
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• v.1 no.2
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• pp.94-103
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• 1988

Diamond anvil cell (DAC) interfaced with a YAG laser heating system has been used to study the phase transformations on perovskite structured titanates ($BaTiO_3$, and $PbTiO_3$) and to synthesize the silicate perovskite phase from the orthopyroxenes of $MgSiO_3$ and $(Mg_{0.87},\;Fe_{0.13})SiO_3$. $BaTiO_3$ and $PbTiO_3$ transform from tetragonal phase to cubic at the pressures of approximately 2.6 GPa and 4.0 GPa at room temperature, respectively. Cubic phases of the both show wide range of stability in the extended in-situ high pressures and high temperature regions. Starting orthoenstatite of $MgSiO_3$ has yielded the perovskite phase as the major structure with ilmenite, gamma-spinel, betta-spinel and stishovite phases at ~38 GPa and ${\sim}1,000^{\circ}C$. $(Mg_{0.87},\;Fe_{0.13})SiO_3$ has shown the perovskite as the major phase with betta-spinel, stishovite and enstatite phases at ~35 GPa and ${\sim}1,000^{\circ}C$. The ilmenite phase does not occur at this condition.