• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.93-100
• /
• 2005

Comparative thickening and dewatering characteristics of municipal wastewater sludge were investigated in terms of separated and combined treatment of primary and secondary BNR sludge. Also, various conditioning methods such as cation polymer addition, steam and ultrasonication treatment were examined to improve dewaterability of sludge. The dewaterability was measured by using specific resistant test, wedge zone simulator and centrifuge. The result of the sludge thickening test revealed that separated thickening was better in terms of solids recovery and supernatant quality. Particularly, the thickening of primary sludge with high solids (about 3.5% TS) showed very poor solid separation. The addition of cation polymer showed better conditioning characteristic for dewatering and the optimal polymer dosage was 0.26% for primary sludge, 0.43% for secondary sludge and 0.38% for combined sludge. Contrary to the result of the thickening, the dewatering test revealed that dewatering of the combined sludge is better than that of separated sludge, representing better solids separation and filtrate quality. The polymer addition was essential to improve dewaterability in filter (belt) press type dewatering but it was inefficient for the dewatering of secondary sludge only. The centrifuge type dewatering showed better performance and the dewaterability was slightly improved when the polymer was added. Based on the results of this research a sustainable sludge treatment process, particularly in terms of the recycle water quality and solids recovery, was proposed.

• Journal of Korean Home Economics Education Association
• /
• v.30 no.4
• /
• pp.93-112
• /
• 2018

We analysed the textbooks of Home Economics in middle school from 1^st to 2009 curriculums to investigate the contents and the portion of Food and Nutrition section. The key words were generated by word cloud technique using text-mining, and the portion of Food and Nutrition section was presented as a ratio of the pages. The core key words of Food and Nutrition section through the curriculums were 'raw food'·'food'·'diet'. In 1^st and 2^nd curriculums, the main key words were related to food materials, condiments and nutrients such as 'vitamin'·'protein'. The words such as 'nutrition'·'eating'·'requirement' were newly appeared in 3^rd, 'portion' in 6^th, and 'diet'·'adolescence' in 7^th curriculum. The mean ratio of Food and Nutrition section in Home Economics was 24.3%. While the portion was as high as 31.8% in 7th it was strikingly reduced to 15.2% in 2009^th. curriculum. Besides, Food and Nutrition section was composed of 10 units of middle level category during the 2^nd and 3^rd curriculums, and was reduced to 2 small units with none of middle level category in 2009^th curriculum. Although the contents of Food and Nutrition section has been developed and adapted to the needs of the society through the curriculums, the portion of Food and Nutrition section in Home Economics has been reduced especially in 2009^th curriculum, which could raise concerns on the health of individuals and communities.

• Information Systems Review
• /
• v.10 no.2
• /
• pp.159-177
• /
• 2008

Since the IMF crisis, the competition among banks in Korea has fiercely intensified. To survive in the severe competition, several leading banks including Industrial Bank of Korea (IBK) have recently developed their own proprietary systems called 'the Next-Generation Systems(NGS).' This case study was to answer several important issues as follows; 1); the reason why a bank make huge investment in the IT infrastructure; 2) the development methodology of the NGS; 3) the new architecture of the NGS; 4) the governance structure of the NGS investment; and 5) the effects of the NGS on the development of new products. To achieve such goals, a systematic tandem interview method and many archival reports from IBK were utilized. The conclusions are summarized as follows: First, the NGS has contributed to the integration and simplification of business processes. Second, new products as demanded in the market can be developed much faster through the NGS. Third, the change management of IT infrastructure is critically important. Fourth, the systems architecture can be different according to the IT governance. Fifth, the alignment of the NGS and business processes is most important to obtain the organizational goals.

• Food Science and Preservation
• /
• v.21 no.3
• /
• pp.350-356
• /
• 2014

Bobsikhae and Bellflower tea-added Bobsikhae samples were prepared. Their general ingredients and useful ingredients were analyzed. Among the general ingredients of the two samples, the crude protein, crude fat, crude ash, and carbonhydrate contents, but not the water, were found to have been higher in the Bellflower tea-added Bobsikhae. To summarize all the results of this study by comparing Bobsikhae with Bellflower tea-added Bobsikhae that used the Bellflower root with edible and medicinal values, their general ingredient contents were similar, but the lactic acid bacteria all tended to be higher in the Bellflower tea-added Bobsikhae. The results of the sensory evaluation showed that the overall taste and general acceptability were better in the Bellflower tea-added Bobsikhae than in the Bobsikhae. Thus, the Bellflower tea-added Bobsikhae is considered ideal for further commercialization. However, it was determined that further studies will be required to show if the bioactive substance would be influenced by the fermentation in the production progress of the Bellflower tea. Such findings and their application to the product development are expected to contribute much to the popularization of Bobsikhae.

• Journal of Korean Society of Transportation
• /
• v.35 no.4
• /
• pp.332-347
• /
• 2017

Analysis of the interaction between the automated vehicles and manual vehicles is very important in analyzing the performance of automated cooperative driving environments. In particular, the automated vehicle platooning can affect the driving behavior of adjacent manual vehicles. The purpose of this study is to analyze the lane change behavior of the manual vehicles in automated vehicle platonning environment and to conduct the experiment and questionnaire surveys in three stages. In the first stage, a video questionnaire survey was conducted, and responsive behaviors of manual vehicles were investigated. In second stage, the driving simulator experiments were conducted to investigate the lane change behaviors of in automated vehicle platonning environments. To analyze the lane change behavior of the manual vehicles, lane change durations and acceleration noise, which are indicators of traffic flow stability, were used. The driving behavior of manual vehicles were compared across different market penetration rates (MPR) of automated vehicles and human factors. Lastly, NASA-TLX (NASA Task Load Index) was used to evaluate the workload of the manual vehicle drivers. As a result of the analysis, it was identified that manual vehicle drivers had psychological burdens while driving in automated vehicle platonning environments. Lane change durations were longer when the MPR of the automated vehicles increased, and acceleration noise were increased in the case of 30-40 years old or female drivers. The results from this study can be used as a fundamental for more realistic traffic simulations reflecting the interaction between the automated vehicles and manual vehicles. It is also expected to effectively support the establishment of valuable transportation management strategy in automated vehicle environments.

• Journal of Mushroom
• /
• v.18 no.3
• /
• pp.254-259
• /
• 2020

Grifola frondosa is a promising new kind of cultivated mushroom owing to its excellent taste and functionality. However, more research is required to determine its value. In this study, the effects of pretreating Grifola frondosa tea by drying, steaming, and warming, on quality characteristics and antioxidant activities were analyzed. There was no difference in sugar, soluble solid, and nitrogen content between dried and steamed tea. The color of the warm pretreated tea was the darkest, and the amino acid content was 462.9 mg/L, which was 1.8 times higher than that of the other pretreatments. Moreover, the warm pretreated tea had the highest total polyphenol and flavonoid content, 14.6 mg/g and 2.2 mg/g, respectively. DPPH and ABTS radical scavenging activities significantly increased with the increase of phenolic compounds. Warming pre-treatment slightly increased the taste preference to 7.0. In conclusion, warming Grifola frondosa before drying was confirmed to improve the extraction of nutrients, antioxidants, and taste preference.

• Journal of Digital Convergence
• /
• v.18 no.2
• /
• pp.163-174
• /
• 2020

The market for electric vehicles is growing due to the public's interest in the environment and the expansion of electric vehicle support projects in terms of government policy. This study surveyed 2,332 people in Jeju, one of the nation's representative areas of electric vehicles, and the higher the perceived value in terms of the total cost of automobile ownership for electric vehicles, the higher the intention to purchase electric vehicles. The higher the level of knowledge and attachment, the higher the intention to purchase electric vehicles. While many previous studies considered economic value mainly as price, the study was conducted to approach economic value in terms of total cost of ownership. Marketing practitioners also look for practical contributions in that they can propose price framing so that customers can judge the economic value of the electric vehicle as a strategic way to increase the intention to purchase the electric vehicle, rather than just the purchase price. can see. In addition, the same research should be conducted in various regions besides Jeju, so that the research results can be generalized.

• Fire Science and Engineering
• /
• v.30 no.3
• /
• pp.138-147
• /
• 2016

As services for citizens' security and protection offered at the national and social levels become more widely recognized across society, the more frequent use of ambulances by patients with both minor and major injuries is being observed. However, the number of safety accidents during transport by ambulances, which are responsible for the prompt transport of patients, has been rising in tandem with the increase in their use. This is due not only to their inconspicuousness both on the road and in other environments where these vehicles are exposed, but also to the high chance of secondary accidents, putting the lives of both patients and emergency responders at risk. It is important to study and develop designs that guarantee protection against safety accidents, noting that ambulances are completely exposed and unprotected on the road on cloudy days and at night-time. In addition, by identifying colors and design motives that enhance the conspicuity of ambulances from a distance and increase their security, emergency responders and patients can be safely protected, the identity of the ambulances can be reinforced and modernized, and the sense oppression which can be visually imposed on patients in a psychologically unstable condition can be eased. Against this backdrop, this study presents the process involved in deriving the exteriors of ambulances in Korea, including their colors and patterns, by examining the established global best practices and identifying the need for more studies into colors, even unconventional ones, that improve their safety.

• Journal of Korea Society of Industrial Information Systems
• /
• v.23 no.5
• /
• pp.103-118
• /
• 2018

This study compared the production inducement effects of primary industries between Korea, China, and Japan for the period from 2000 to 2014, by examining the forward and backward linkage effects using the World Input-Output Tables. Although research on the industrial effect of primary industries has been conducted actively, this study is contributive since it compares the differences in industrial linkage effects between Korea, China, and Japan. According to Fisher(1939)'s and Clark(1957)'s classifications of primary industries, this study classified agriculture, forestry, fishing, and mining industries as primary industries. The analysis methodology of this study is to use the World Input-Output Tables to create the industry linkage model between Korea, China, and Japan, and then conduct a comparative analysis. According to the results of this study, the forward and backward linkage effects of agriculture industry between Korea, China, and Japan are significantly different, while the forward and backward linkage effects of forestry and fishing industries between Korea, China, and Japan are partially different. By comparing the changes in industrial dependencies of primary industries due to the 4th Industrial revolution between the three countries, this study suggested the future development direction of primary industries.

• Journal of The Korean Association For Science Education
• /
• v.24 no.5
• /
• pp.825-832
• /
• 2004

In this study, the history of science (HOS) presented at the chapter of "Inquiry of science" in high school science textbooks developed under the 6th and 7th national curriculam was analyzed and compared. A total of 57 sections from 19 textbooks (6th: 12 textbooks, 7th: 7 textbooks) were analyzed in terms of the domain and the presentation level of the HOS described. The results revealed that the frequencies of HOS per page of the textbooks under the 7th curriculum tended to be higher than those under the 6th one in all the domains (conceptual, procedural, and contextual), of which the difference in conceptual domain was statistically different. Regarding the describing level (limited and extensive) at the presentation of the HOS, the frequencies of extensive descriptions per page for the textbooks under the 7th curriculum were also significantly higher than those under the 6th one. The improvement of frequencies and presentation level of HOS in 7th national curriculum could help students to understand scientific concept and nature of science and to have an interest about science.