• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.4
• /
• pp.267-274
• /
• 2018

Though the wet bottom ash has been used as a type of lightweight aggregate, dry bottom ash, new type bottom ash from coal combustion power plant, has scarcely researched. It is excellent lightweight aggregate in the view point of construction material. This study is performed to check the applicability of dry bottom ash as a fine aggregate in lightweight aggregate concrete, by analyzing various properties of fresh and hardened concrete. We get results that the slump of concrete is within the target range at less than 75% replacement rate of dry bottom ash, the air content is not affected by the replacement rate of dry bottom ash, the bleeding capacity is less than $0.025cm^3/cm^2$ at 75% under of the replacement rate of dry bottom ash, and the compressive strength of concrete show 90% or more comparing the base mix while initial strength development is a little low. Oven dry unit weight of concrete is reduced by 8.9% when replaced 100% dry bottom ash, and dry shrinkage tends to decrease depending on increase of replacement rate of dry bottom ash. Modulus of elasticity of concrete shows no decease at 50% over of the replacement rate of dry bottom ash, while modulus of elasticity of concrete decreases when the replacement rate increases further. The dry bottom ash, when used as a fine aggregate in lightweight concrete, can be used effectively without any deterioration in quality.

• Membrane Journal
• /
• v.29 no.3
• /
• pp.173-182
• /
• 2019

Much research has been made for finding new and eco-friendly alternative sources of energy to solve the problems related with the pollution caused by emissions of greenhouse gases such as carbon dioxide as the use of fossil fuels increases worldwide. Among them, fuel cells draws particular interests as an eco-friendly energy generator because only water is obtained as a by-product. Anion exchange membrane-based alkaline fuel cell (AEMFC) that uses anion exchange membrane as an electrolyte is of increased interest recently because of its advantages in using low-cost metal catalyst unlike the PEMFC (potton exchange membrane fuel cell) due to the high-catalyst activity in alkaline conditions. The main properties required as an anion exchange membrane are high hydroxide conductivity and chemical stability at high pH. Recently we reported a chemically crosslinked poly(2-dimethyl-1,4-phenylene oxide) (PPO) by reacting PPO with N,N,N',N'-tetramethyl-1,6-hexanediamine as novel anion exchange membranes. In the current work, we further developed the same crosslinked polymer but having enhanced physicochemical properties, including higher conductivity, increased mechanical and dimensional stabilities by using the PPO with a higher molecular weight and also by increasing the crosslinking density. The obtained polymer membrane also showed a good cell performance.

• The Journal of Society for e-Business Studies
• /
• v.24 no.2
• /
• pp.71-89
• /
• 2019

In order to come up with satisfying product and improvement, firms use traditional marketing research methods to obtain consumers' opinions and further try to reflect them. Recently, gathering data from consumer communication platforms like internet and SNS has become popular methods. Meanwhile, with the development of information technology, mobile companies are launching new digital products for children to protect them from harmful content and provide them with necessary functions and information. Among these digital products, Kids Phone, which is a wearable device with safe functions that enable parents to learn childern's location. Kids phone is relatively cheaper and simpler than smartphone but it is noted that there are several problems such as some useless functions and frequent breakdowns. This study analyzes the reviews of Kids phones from domestic mobile companies, identifies the characteristics, strengths and weaknesses of the products, proposes improvement methods strategies for devices and services through SNS consumer analysis. In order to do that customer review data from online shopping malls was gathered and was further analyzed through text mining methods such as TF/IDF, Sentiment Analysis, and network analysis. Customer review data was gathered through crawling Online shopping Mall and Naver Blog/$Caf\acute{e}$. Data analysis and visualization was done using 'R', 'Textom', and 'Python'. Such analysis allowed us to figure out main issues and recent trends regarding kids phones and to suggest possible service improvement strategies based on sentiment analysis.

• Journal of the Economic Geographical Society of Korea
• /
• v.24 no.3
• /
• pp.313-329
• /
• 2021

This study analyzed the characteristics of the management crisis, the level of resilience, and the alternatives based on the companies' self-evaluation of the game industry in Daegu. The Daegu game industry, which started spontaneously in the late 1990s, grew rapidly until the late 2000s with the support of the government and supporting organizations. However, from the mid-2010s, it has entered a period of recession due to the number of companies that failed to respond to the saturation of the mobile game market and fierce competition at home and abroad. In response, some game companies turned the crisis into an opportunity to strengthen their competitiveness by pursuing challenging strategies for product differentiation and pioneering new markets. On the other hand, companies that were passive in responding to the crisis have not get out of the management crisis. In addition, in terms of the resilience level of game companies in Daegu, the level of immediate response to shock(rapidity) and replacement of the damaged part(redundancy) was low, but the level of mobilizing sufficient resources internally(resourcefulness) was high. However, as the Daegu game industry is facing more complex multi-spatial-scale environmental changes than in the past, its resilience should be strengthened through strategies that can compensate for weaknesses in terms of the game industry ecosystem beyond individual company-level efforts.

• Food Science and Industry
• /
• v.50 no.2
• /
• pp.2-11
• /
• 2017

Packaging is the last defensive barrier that protects food products from insect infestation during storage. However, though packaging films are hermetically sealed, insects can still be attracted by strong olfactory cues and penetrate through packaging materials, resulting in contamination. Insect contamination may cause consumers to be repulsed by contaminated food products. Especially, it is well known that stored-product insects cause critical problems in the cereal industry by inducing quantitative and qualitative damages to the grain products. The contaminations are caused by insects' metabolic byproducts and body parts, consequentially caused customer repulsion. Therefore, it is necessary to repel and control insects. However, management systems for storage insects in food industry have been inadequate for many years. Synthetic pesticides has been widely used, but pesticides may accumulate in foods, causing acute and chronic symptoms in consumers. For this reason, there is a growing need for the development of natural insecticides that can replace synthetic pesticides. Thus, various reports about anti-insect packaging materials and strategies to repel insects were introduced in this study. Furthermore, we suggested new strategies to develop an insect-repelling active packaging materials which could be applied in the food packaging industry.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.47 no.1
• /
• pp.1-7
• /
• 2021

With increasing interest in the effectiveness and safety of sunscreen worldwide, research on the development of new inorganic sunscreen is also gaining momentum. In the present study, non-nano sized needle type zinc oxide, which can meet the regulation of nano-material as a recent problem, has been synthesized and surface-modified with cetyl alcohol to obtain needle type zinc oxide powder. Here, we also investigated their physical properties and evaluated their potential application as sunscreens. As a result of the experiment, the sunscreen with needle type zinc oxide powder, which was non-nano, showed similar UV-protection properties and transparency compare to that of 40nm size zinc oxide. It was further confirmed that the UV blocking effect was significantly increased when the needle type zinc oxide dispersion was applied to the sunscreen. Therefore, although the needle type zinc oxide is non-nano (200 nm) material, it has the potential to be applied to the product as an excellent transparency (improvement of whiteness), UV protection efficacy and smooth texture.

• Journal of the Korea Institute of Building Construction
• /
• v.22 no.3
• /
• pp.251-258
• /
• 2022

In the cement industry, in order to reduce CO₂ emissions, technology for raw materials substitution and conversion, technology for improving process efficiency of utilizing low-carbon new heat sources, and technology for collecting and recycling process-generated CO₂ are being developed. In this study, we conducted a basic experiment to contribute to the development of CSC that can store CO₂ as carbonate minerals among process-generated CO₂ capture and recycling technologies. Three types of CSC clinker with different SiO₂/(CaO+SiO₂) molar ratios were prepared with the clinker raw material formulation, and the characteristics of the clinker were analyzed. As a result of analysis and observation of CSC clinker, wollastonite and rankinite were formed. In addition, as a result of the carbonation test of the CSC paste, it was confirmed that calcite was produced as a carbonation product. The lower the SiO₂/(CaO+SiO₂) molar ratio in the CSC clinker chemical composition, the lower the wollastonite production amount, and the higher the rankinite production amount. And the amount of calcite production increased with the progress of carbonation of the CSC paste specimen. It is judged that rankinite is more reactive in mineralizing CO₂ than wollastonite.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.4
• /
• pp.1-13
• /
• 2021

In this study, we tried to present suggestions to the Gyeongsangbuk-do tourism officials to satisfy them with experiential tourism resources and to revitalize their participation in the program. Therefore, the implications of this study are as follows. First, research on the satisfaction of experiential tourism programs and the willingness to participate in them is carried out, suggesting that it is a prerequisite for the transformation of the perception of tourists' participation in the Corona era. Second, it is necessary to make it a small experience tourist space that can provide non-face-to-face service utilizing the characteristics of contact technology, and to provide tourists with unique attractions against product discrimination and customer service. Third, through the introduction of non-face-to-face experience programs and expansion of services, the limited and macroscopic environment and social phenomenon of tourism activities in the Corona era, a new perception can be instilled. Fourth, visitors can expect to revitalize the tourism industry through the development and discovery of various programs. Thirdly, it will be possible to revitalize the local economy by giving meaning to the satisfaction of experiential tourism programs to tourists from all over the region's tourism business.

• The Journal of the Korea Contents Association
• /
• v.21 no.12
• /
• pp.748-756
• /
• 2021

In this study, as the first attempt to develop an experiential game tourism program using Korean classical literature, the primary research was conducted on Kim Soo-Jang and his anthology "Hae Dong Ga Yo". To this end, a theoretical review of the value of hands-on games and Korean classical literature as tourism content was conducted first. Afterwards, the consumers for the program were set up into three categories: family unit, MZ generation including lovers, and foreigners. A survey was conducted to confirm the program preference of each group. According to the analysis framework, the main value of each historical and cultural resource in "Hae Dong Ga Yo" and seven sijo pieces created by Kim Soo-Jang was discovered and, based on the survey, the preferences of the consumer related to the target were analyzed. Accordingly, the narrative structures were organized differently for each group. An adventure plot was designed for the family unit, a love plot for MZ generation and lovers, and a mixture of adventure and love for foreigners. Utilizing stories from Kim Soo-Jang and his works, which are rarely used despite their value, this study attempted to develop them into hands-on game tourism programs to create new outlets in terms of both Korean classical literature and the tourism area. In the future, if various Joseon literati are discovered and their storytelling is continued, we can expect the vitalization of the travel product line with the concept of classical literature travel.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.921-926
• /
• 2022

Sugar solutions (5%, 10%, 15% and 20%) were tested by seven sensors of Astree E-Tongue for selecting a sensor for sweetness. NMS sensor was chosen as a sensor for sweetness among two sensors (PKS and NMS sensors selected in first stage) by considering precision, linearity and accuracy. Sugar, fructose, glucose and xylitol (5%, 10% and 15%) were tested by E-tongue. The principal component analysis (PCA) result by E-Tongue with seven sensors at 5% concentration level of four sweetners was not satisfactory (Discrimination index was -0.1). On the other hand, the relative NMS sensor response values were derived as 1.08 (fructose), 0.99 (glucose) and 1.00 (xylitol) comparing to sugar. Only the E-Tongue relative glucose response 0.99 was different from 0.5~0.75 of the relative sweetness range reported as the human sensory test results. Considering the excellent precision (%RSD, 1.53~3.64%) of E-Tongue using NMS single sensor for three types of sweeteners compared to sugar in the concentration range of 5% to 15%, replacing sensory test of sweetened beverages by E-Tongue might be possible for new product development and quality control.