• Korean Chemical Engineering Research
• /
• 제59권2호
• /
• pp.219-224
• /
• 2021

Ion flotation is an efficient method to remove metal ions from aqueous solution. In this work, ion flotation was applied to calcium removal from aqueous solution. The parameters used included sodium stearate (SS) and sodium dodecyl sulfate (SDS) as collectors, 1-butanol and 1-propanol as frothers, pH, and air-flow rate. An L16 orthogonal array was chosen according to the mentioned factors and levels, and experimental tests were conducted according to the Taguchi orthogonal array. The results showed that all of the factors except one had significant effect on the flotation performance. The percentage contribution of parameters showed that type of frother and type of collector made the greatest (43.14%) and the lowest (9.86%) contribution, respectively. In optimal conditions, the recovery of Ca (II) ion was 45.67%. Also, the results illustrated that the Taguchi method could predict calcium removal from aqueous solution by ion flotation with 2.63%. This study showed that the use of ion flotation was an effective method for Ca (II) ion removal from aqueous solution.

• International Journal of Contents
• /
• 제18권1호
• /
• pp.56-64
• /
• 2022

To improve the cooperation ability of emergency entities, in this research, the emergency activities model, skill contribution degree, entity-relationship strength, activity continuity, and emergency entity cooperation degree were defined. Emergency entity cooperation degree and emergency activity continuity table were constructed with emergency cases, emergency plans, and emergency drill plans, and factors were further excavated which affected them. In this paper, we focus on the factors which affect the cooperation ability of emergency entities, the relationship between the emergency cooperation ability and the number of cooperation, entity-relationship intensity, emergency activity frequency, and skill contribution of fire entities and medical entities were obtained. These data results are of great significance to decision-makers in formulating emergency rescue and emergency plans.

• 한국공간구조학회논문집
• /
• 제5권3호
• /
• pp.91-100
• /
• 2005

본 연구는 구조물의 정량적 강성설계 기법 개발, 즉 부재 단위의 강성 재설계를 통한 전역 자유도 변위의 정량적 조절 기법개발을 궁극적 목적으로 한다. 이를 위하여 본 연구에서는 전역 자유도에 대한 부재의 변위기여도계수와 내력기여도계수를 유도하고, 이를 이용하여 특정 변위를 정량적으로 예측, 제어할 수 있도록 부재 강성과 특정 변위간의 상관식을 유도 제시하였다. 간단한 예제 구조물의 해석과 제안식 적용을 통한 변위 예측값 사이의 비교를 통하여 제안식을 검증하였다. 정정구조물의 경우 본 상관식은 정해로서, 이를 이용하여 폭정 변위를 원하는 목표치로 정확하게 제어할 수 있으며, 부정정구조물의 경우에도 부재 내력 재분배에 의한 오차가 발생하기는 함에도 불구하고 각 부재 강성과 특정 변위간의 상관성과 경향을 제시함으로써 매우 유용하게 활용될 수 있다. 본 연구에서 제안하는 정량적 변위 제어 기법은 강성설계가 전체 설계 결과를 지배하게 되는 대 공간구조물 또는 초고층건물의 설계 시 유용할 것으로 기대된다.

• Bulletin of the Korean Chemical Society
• /
• 제25권10호
• /
• pp.1525-1530
• /
• 2004

Mutagen X (MX) exists in our drinking water as the bi-products of chlorine disinfection. Being one of the most potent mutagen, it attracted much attention from many researchers. MX and its analogs are synthesized and modeled by quantitative structure activity relationship (QSAR) methods. As a result, factors affecting this class of compounds have been found to be steric and electrostatic effects. We tried to collect all the data available from the literature. With both CoMFA and CoMSIA various combinations of physiochemical parameters were systematically studied to produce reasonable 3-dimensional models. The best model for CoMFA gave $q^2$ = 0.90 and $r^2$ = 0.97, while for CoMSIA $q^2$ = 0.85 and $r^2$ = 0.94. So the models seem to be reasonable. Unlike previous result of CoMFA, in our case steric parameter alone gave the best statistics. Although the steric contribution was found to be the most important in both CoMFA and CoMSIA, steric parameter along with electrostatic parameter produced slightly better model in CoMSIA. Overall, steric contribution is clearly the most important single factor. However, when we compare chlorine and bromine substitution, chlorine substitution can be more mutagenic. This indicates that other factors such as electrostatic effect also influence the mutagenicity. From the contour maps, steric contribution seems to be focused on rather small area near C6 substituent of the furanone ring, rather than C3 substituent. Therefore the locality of steric contribution can play a significant role in mutagenicity.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2012년도 춘계학술대회
• /
• pp.21-22
• /
• 2012

• 한국관광식음료학회지:관광식음료경영연구
• /
• 제16권2호
• /
• pp.17-31
• /
• 2005

Recently, hotel industry has realized the importance of food and beverage sales for the profit maximization, and the focuses on restaurant management has been growing. Accordingly, menu management in the F/B department is one of the most key factors determining the success or failure of business. Therefore, in this study, entree menu items of french restaurant in the deluxe hotel was analysed with presently theorized model of menu analysis, classified into four menu items. Also it was analyzed how those classified menu items influence on sales, number of sold, food cost percentage, contribution margin And, proper ways was presented to make restaurant managers and menu planner in order to increase food operation sales through proper modifications and methods on various menu analysis matrix. In Pavesic's menu analysis method, all of menu items have impact on the sales, number of sold, contribution margin and Primes, Sleepers do so on the food cost. The finding of this study was that Pavesic's menu analysis is superior to menu analysis in terms of the sales, number of sold, food cost percentage, contribution margin. Therefore, Pavesic's menu analysis is useful and efficient method in order to conduct menu engineering.

• 한국관광식음료학회:학술대회논문집
• /
• 한국관광식음료학회 2005년도 학술논문발표집
• /
• pp.80-91
• /
• 2005

Recently, hotel industry has realized the importance of food and beverage sales for the profit maximization, and the focuses on restaurant management has been growing. Accordingly, menu management in the F/B department is one of the most key factors determining the success or failure of business. Therefore, in this study, entree menu items of french restaurant in the deluxe hotel was analysed with presently theorized model of menu analysis, classified into four menu items. Also it was analyzed how those classified menu items influence on sales, number of sold, food cost percentage, contribution margin And, proper ways was presented to make restaurant managers and menu planner in order to increase food operation sales through proper modifications and methods on various menu analysis matrix. In Pavesic's menu analysis method, all of menu items have impact on the sales, number of sold, contribution margin and Primes, Sleepers do so on the food cost. The finding of this study was that Pavesic's menu analysis is superior to menu analysis in terms of the sales, number of sold, food cost percentage, contribution margin. Therefore, Pavesic's menu analysis is useful and efficient method in order to conduct menu engineering.

• The Journal of Asian Finance, Economics and Business
• /
• 제6권2호
• /
• pp.75-82
• /
• 2019

The paper aims to investigate the impacts of long-term savings motives on fostering household participation and contribution to savings mechanisms in rural Vietnam. The paper is organized in five parts: introduction, data description, methodology, empirical results, and conclusion. The quantitative methodology is employed and three simultaneous estimation methods, including instrumental variable model, two-step model, and Heckman model are used to test these impacts as well as the robustness of results. In each model, the paper examines the impacts of independent factors on both household participation and household contribution to savings mechanisms. Two sets of independent variables: long-term savings motives (profit-making investment, accumulation for big expenditure, providing for old age, and cost of educations) and control variables (dependency rate, number of people in household, and household wealth) are in each model. A set of dataset of 2,314 households for analysis is obtained from household survey in rural Vietnam. Robust statistical findings indicate that profit-making investment emerged to be the strongest motive fostering household participation to savings mechanisms while other long-term savings motives have little or no impact on fostering household participation to savings mechanisms. In addition, education investment encourages household contribution to savings mechanisms in rural Vietnam.

• 품질경영학회지
• /
• 제46권4호
• /
• pp.1015-1028
• /
• 2018

Purpose: This study attempts to find how the cultural marketing activities utilizing cultural space affect firm's brand image and brand loyalty, and whether this culture marketing technique is recognized as a social contribution activity by potential customers and thereby influence brand image and loyalty. Methods: The data was collected by using the structured questionnaires to consumers who have experience using the Naver Library, Starfield Library, and Hyundai Card Library. The proposed research model is tested using 178 valid questionnaires using Smart PLS 2.0. Results: This research indicated that among cultural marketing factors, cultural support and cultural promotion have little impact on brand image, whereas culture firm influence brand image. Brand image also had an impact on brand loyalty, but it was found that public libraries operated by companies were not recognized as corporate social contribution activities, nor did they have an impact on the formation of the company's brand image. Conclusions: The study offered a theoretical and empirical foundation for future research by empirically identifying the relationship between cultural marketing and brand image and loyalty and confirmed the coordinating effect of social contribution activities between a cultural firm and its brand image.

• 한국컴퓨터정보학회논문지
• /
• 제14권4호
• /
• pp.153-160
• /
• 2009

본 논문에서는 온라인 커뮤니티에서 어떻게 지식공헌이 이루어지는지를 살펴보고자 온라인 커뮤니티 사용자들의 지식공헌에 영향을 미치는 요인들을 실증적 연구를 통해 규명하고자 하였다. 자기표현이론과 조직시민행동이론을 토대로 연구모형을 설정하고 네 개의 가설을 제안하였다. 온라인 커뮤니티 참여자 192명의 설문 조사를 PLS로 분석한 연구의 결과에서, 온라인 커뮤니티 사용자들의 자기표현과 혁신성, 조직시민행동 및 감정적 동질감등이 지식공헌에 긍정적인 영향을 미치는 것으로 나타났다. 이외에 온라인 커뮤니티에 대한 본 연구결과에 대한 학문적 실무적 의미를 논의하였으며, 향후 연구에 대한 시사점도 언급하였다.