• Particle and aerosol research
• /
• v.19 no.3
• /
• pp.89-100
• /
• 2023

In our previous study, a wire-plate type electrostatic precipitator (ESP) was developed to collect bioaerosols of 100 nm size. In the study, various flow rates (40 ~ 100 L/min) and applied voltages (3 ~ 10 kV) were tested for experiment. In this study, numerical analysis was performed for the ESP of the previous study with the same flow rates and applied voltages, but with varying the size of bioaerosols to 0.04 ~ 2.5 ㎛. Overall, the numerical analysis results well predicted the experimental data. Bioaerosols of 0.1 ~ 0.5 ㎛ showed the minimum collection efficiency for all conditions because of low charge number. The effect of the ionic wind generated by the corona discharge was calculated. However, the ionic wind did not affect much the collection efficiency. The aerosol collection in the ESP of this study was due to the electrostatic force generated by particle charge in the electric field. This numerical study on the ESP can be used for the design and optimization of higher flow rate (> 100 L/min) ESP.

• Journal of Korean Society of Rural Planning
• /
• v.30 no.2
• /
• pp.25-34
• /
• 2024

This study is a basic study for reorganizing the facility system of agriculture and rural areas necessary for establishing a rural spatial plan. Accordingly, the newly implemented rural spatial planning system was briefly reviewed. As the scope of the study, the facility-related laws and the classification and classification system of facilities of previous studies were set as the scope of the study. In order to reorganize the facility system in rural areas necessary for establishing a rural space plan, this study compared and analyzed the facilities according to the laws related to the facilities and the use of previous studies. As a result of analyzing 21 target sites for rural agreements with 12 sectors of service facilities in rural areas as indicators, 14 facilities in 8 sectors were found to be commonly introduced for the establishment of living areas in rural areas or regional development. However, the classification of production space facilities related to agriculture as functional facilities necessary for rural life was insufficient. Accordingly, when considering the specificity of rural areas, it is necessary to classify facilities of living spaces in rural areas and production space of agriculture according to their use.

• The Korean Journal of Applied Statistics
• /
• v.30 no.3
• /
• pp.377-390
• /
• 2017

When conducting a survey, item nonresponse occurs if the respondent does not respond to some items. Since analysis based only on completely observed data may cause biased results, imputation is often conducted to analyze data in its complete form. The panel study is a survey method that examines changes of responses over time. In panel studies, there has been a preference for using information from response values of previous waves when the imputation of item nonresponses is performed; however, limited research has been conducted to support this preference. Therefore, this study compares the performance of imputation methods according to whether or not information from previous waves is utilized in the panel study. Among imputation methods that utilize information from previous responses, we consider ratio imputation, imputation based on the linear mixed model, and imputation based on the Bayesian linear mixed model approach. We compare the results from these methods against the results of methods that do not use information from previous responses, such as mean imputation and hot deck imputation. Simulation results show that imputation based on the Bayesian linear mixed model performs best and yields small biases and high coverage rates of the 95% confidence interval even at higher nonresponse rates.

• Journal of Service Research and Studies
• /
• v.8 no.4
• /
• pp.77-88
• /
• 2018

Collaboration works on R&D project have many characteristics in interoranizational relationships. There are many variables on explaining the their relationships. In the previous study, I chose some relevant variables and some hypotheses. Base on service marketing theories and relationship marketing perspective I suggest 5 hypotheses. Independent variables are fairness and quality, and dependent variable is loyalty. And trust are treated as the intervening variable between the independent variables and dependent variable. To test the research model and some hypothesis empirically, I collected the data using the questionnaire. Sample size was 448, it was enough to analyze statistically. Data were analysed using the SPSS and AMOS. In the previous study, H1($fairness{\rightarrow}trust$), H2($quality{\rightarrow}trust$), H5($trust{\rightarrow}loyalty$) were accepted, but H3 and H4 were rejected. The reason H3($fairness{\rightarrow}loyalty$) and H4($quality{\rightarrow}loyalty$) were not accepted might be attributed to the fact that trust was the mediating variable between fairness and loyalty, quality and loyalty. Specific research methodologies and statistical findings from AMOS were referred in the previous study(Jeong 2018). In this study, I suggested some hypotheses on the mediating role trust between fairness and loyalty and service quality and loyalty. Using the PROCESS-macro, I found that trust was the mediating variable between fairness and loyalty as well as service quality and loyalty. This research is the complementary and extended study from previous research.

• Journal of Internet Computing and Services
• /
• v.21 no.6
• /
• pp.13-21
• /
• 2020

The Android author identification study can be interpreted as a method for revealing the source in a narrow range, but if viewed in a wide range, it can be interpreted as a study to gain insight to identify similar works through known works. The problem found in the Android author identification study is that it is an important code on the Android system, but it is difficult to find the important feature of the author due to the meaningless codes. Due to this, legitimate codes or behaviors were also incorrectly defined as malicious codes. To solve this, we introduced the concept of survival network to solve the problem by removing the features found in various Android apps and surviving unique features defined by authors. We conducted an experiment comparing the proposed framework with a previous study. From the results of experiments on 440 authors' identified apps, we obtained a classification accuracy of up to 92.10%, and showed a difference of up to 3.47% from the previous study. It used a small amount of learning data, but because it used unique features without duplicate features for each author, it was considered that there was a difference from previous studies. In addition, even in comparative experiments with previous studies according to the feature definition method, the same accuracy can be shown with a small number of features, and this can be seen that continuously overlapping meaningless features can be managed through the concept of a survival network.

• The Journal of Information Systems
• /
• v.30 no.4
• /
• pp.173-202
• /
• 2021

Purpose This study explored overall phenomena in context such as YouTube channel operation, strategy, and profit generation through interviews with two research participants who started their own businesses and are recognized as influencer on YouTube and analysis of viewer responses to uploaded contents. With the explosive growth of YouTube content provision and use, previous studies on YouTube are only being conducted individually on YouTube's content, influence, and content providers, so it is need to explore YouTube channel operations and the effect of revenue generation in context from an integrated perspective. Therefore, the purpose of this study is to present an integrated model that provides a specific process by contextually linking the factors and results influencing YouTube channel operation and revenue generation phenomena to individuals and companies who are trying to operate YouTube channels for the first time. Design/methodology/approach This study systematized and structured the overall phenomena in context such as YouTube channel operation, communication strategy, effect on revenue generation, and YouTube channel operation results by selecting interview subjects and collecting data through interviews, and analyzing viewer reactions (likes, comments, etc.). Due to the lack of previous studies exploring integrated phenomena, research analysis used Strauss & Corbin (1998)'s grounded theory approach, which presented inductive research methods to discover new theories by structuring concepts and categories based on detailed observations and information provided by interviewees. Findings The academic implication of this study is that while previous studies are conducted as individual studies on YouTube's content, influence, and content providers in the current situation where YouTube content provision and use are exploding, it integrally explores and presents an integrated model throughout the process. In addition, taking into account the lack of previous studies, it can be found in the aspect of using the grounded theory approach, an inductive theory approach that establishes a new theory. The practical implications can be found in that it presented practical directions to beginners who want to start operating YouTube channels by identifying operational preparations, communication strategies with viewers, and response management strategies.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.16 no.6
• /
• pp.119-130
• /
• 2021

This study is a study on the regulatory focus and entrepreneurship that affect entrepreneurial motivation under uncertainty. In the empirical analysis results between the prevention focus, risk taking, and economic entrepreneurial motive, which were not observed in previous studies in Korea, this study tried to supplementally verify the previous studies by focusing on the limitations of the sample suggested as limitations. In particular, under a special external environment where uncertainty is deepening due to COVID-19 and the economic situation is being severely hit, we regressively analyze regulatory focus and risk taking, which are innate personal characteristics that can affect entrepreneurial motives. The mediating effect of risk taking was demonstrated. As a result of the empirical results, it was found that the prevention focus, risk taking, and economic entrepreneurial motivation had a significant effect, and it was shown that risk taking had a mediating effect between the prevention focus and the economic entrepreneurial motivation. This result is meaningful as a result not observed in previous studies, and it is judged that the control focus, which is an individual characteristic with a large innate tendency, interacts with the risk taking of the acquired tendency to influence the motivation to start a business. The results of this study can be of practical help by understanding and concentrating on regulatory focus and risk taking when conducting entrepreneurship or entrepreneurship education programs to entrepreneurs who dream of or want to start a business amid the growing uncertainty of the external environment. On the other hand, it is necessary to confirm whether these results, which are different from previous studies, are the effect of sample diversity or the external environment such as Corona 19, and re-verification through additional research is needed in the future.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.6
• /
• pp.317-326
• /
• 2020

Previous studies have suggested that individuals need to invest in the accumulation of career competencies. To demonstrate how to acquire career competencies, a model consisting of the knowing why, knowing how, and knowing whom competencies was actively discussed in the previous studies. This study seeks to identify the relationships among these competencies based on three ways of knowing, and their effects on perceived work performance. Furthermore, this study tried to identify the importance of each of these competencies in predicting perceived individual performance in the business workplace environment. The findings showed that the knowing why, knowing how, and knowing whom competencies all have a statistically significant positive influence on perceived individual work performance. Also, the study results showed the relative importance of the three competencies for perceived work performance. Specifically, the study results showed that the effects of the knowing why and knowing whom competencies are greater than the effect of the knowing how competency. The theoretical and practical implications of the study results were provided, including empirical evidence of the validity of the career capital model, the appropriateness of the career competency model based on the three ways of knowing, and assignment of resources for the acquisition of career competencies.

• Journal of Korean Society for Quality Management
• /
• v.45 no.3
• /
• pp.403-426
• /
• 2017

Purpose:?The purpose of this study is to analyze the causal relationship between top management 's leadership and construction quality management activities that affect construction management performance based on construction quality management. Methods:?As its method, the causal relationship between the leadership of top management and the key management factors of construction quality management activities affecting management performance is analyzed by using the structural equation model. The construction companies used in the analysis sample conducted surveys on companies that are conducting ISO, KOSHA, OHSAS, DQC, and so on. Results:?It was revealed that top management's leadership has a great influence on management performance and all management factors of construction quality management activities. However, safety management does not affect the management performance of construction quality management activities. And top management's leadership on management performance are explained by the mediating effect of cost, time, quality and communication among management factors of construction quality management activities. Conclusion:?In the previous study, the quality management activities and the ISO - based integrated total quality management system (TQM) applied in the manufacturing or service industries were presented as empirical results. However, this study presents the results of different studies by presenting empirical study results by selecting time, cost, quality, safety and communication as key management factors of quality management activities of construction companies through reviewing and analyzing previous studies in construction field.

• Journal of Information Technology Services
• /
• v.15 no.1
• /
• pp.269-287
• /
• 2016

In general, service failure occurs inevitably and the customers who experienced the greater dissatisfaction have the higher expectations of service recovery. However, most of the previous studies have focused on the evaluation and risk factors of pre-service quality. Thus, this study is contrary to the numerous previous studies and focus on the effectiveness of mobile application advertisement users' perceived perception on service recovery after service fails. A research model presented in this study is based on the Equity Theory and deeply evaluated the effectiveness of Distributive Justice, Interactional Justice, and Authenticity Relevance on Service Recovery. The survey of this study was conducted among 286 users who have experienced a services recovery of mobile application advertising. As a result, among all the factors of users of mobile application advertising, Distributive Justice, Interactive Justice, and Relevance have a positive impact to Satisfaction. In addition, Distributive Justice, Authenticity and Satisfaction also have a positive impact to Trust. Ultimately, Satisfaction and Trust have a positive impact to Service Recovery. The results of this study are expected as a reference for presenting a new business model for mobile application advertising industry, reducing business risk and enriching the related researches.