• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.1
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• pp.49-56
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• 2021

The purpose of this study is to develop a methodology to select a cluster of night traffic accidents using CRP (Continuous Risk Profile) analysis. the other purpose of this study is to present the characteristics of the traffic accident cluster section selected at night using CRP analysis. The CRP analysis was performed considering traffic volume of target routes through traffic accident data. In addition, variables were set according to the freeway sections. the method of subtracting the daytime CRP from the nighttime CRP was used to analyze the nighttime traffic accident. As a result, Using the CRP analysis, the sections of hotspot were identified and plotted based on traffic accidents. Also, the sections where traffic accidents are frequent were those where IC or Tunnels were installed, and there was a deviation from the general section. In conclusion, CRP analysis could be used to calculate the frequent section of specialized traffic accidents at night, and it was selected as a point in need of improvement due to the frequent occurrence of specialized traffic accidents at night in the section where IC or tunnel facilities are installed. In addition, it is inferred that the number of specialized traffic accidents at night in the section where IC or tunnel facilities are installed is a factor in the problem of night visibility due to lighting facilities.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.385-393
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• 2022

This study conducted a survey of social welfare facility workers in Mokpo, Jeollanam-do from May 21 to May 24, 2019 to empirically analyze the effect of job rotation on work efficiency and job satisfaction. Individual development of job rotaion (independent variable), job satisfaction (dependent variable), work efficiency (mediating variable), and work overload (moderating variable) were set as variables of the research model. For the questions of all variables, the Likert 5-point scale was used, the SPSS version 24.0 was used as an empirical analysis tool to verify the hypothesis, descriptive statistics and reliability analysis were performed, and the mediating effect and moderating effect were analyzed using SPSS PROCESS macro 4.0. The results of this study are as follows. First, it was analyzed that the individual development of job rotation did not significantly affect job satisfaction. Second, it was found that work efficiency fully mediated the relationship between individual development of job rotation and job satisfaction. Finally, it was found that the interaction term between work efficiency and job overload had a negative effect on job satisfaction and had a moderated mediating effect.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.287-301
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• 2022

This study aims to propose a crane-tip control method to intuitively control the end-effector vertically or horizontally for improving the crane work efficiency and to confirm the control performance. To verify the control performance based on experimental variables, a laboratory-scale crane was manufactured using an electric cylinder. Through a forward and reverse kinematics analysis, the crane was configured to output the position coordinates of the current crane-tip and the joint angle at each target point. Furthermore, a method of generating waypoints was used, and a dead band using lateral boundary offset (LBO) was set. Appropriate parameters were selected using bang-bang control, which confirmed that the number of waypoints and LBO radius were associated with positioning error, and the cylinder speed was related to the lead time. With increased number of waypoints and decreased LBO radius, the positioning error and the lead time also decreased as the cylinder speed decreased. Using the proportional control, when the cylinder velocity was changed at every control cycle, the lead time was greatly reduced; however, the actual control pattern was controlled by repeating over and undershoot in a large range. Therefore, proportional control was performed by additionally applying velocity gain that can relatively change the speed of each cylinder. Since the control performed with in a range of 10 mm, it was verified th at th e crane-tip control can be ach ieved with only th e proportional control to which the velocity gain was applied in a control cycle of 20 ms.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.87-97
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• 2021

To investigate the current pest management status in Korea, a survey was conducted from 151 students and graduates in the Korea National College of Agriculture and Fisheries (KNCAF) by on-line. The questionnaire consists of two divisions, basic questions and pest control questions. The basic questions were including the respondent's age, academic status, cultivating crops and cultivating area. The pest control questions were including pest control methods, pesticide selection rationale, and pest forecasting methods. As a summary of basic questions, the respondents in their 20s accounted for 91.2%. Moreover, 34.5% of the respondents had over 3 hectares of cultivating area. The cultivating methods were differed by cultivating crops. As a summary of pest control questions, major control methods were using the conventional chemicals (>66%). To understand the pesticide selection rationale, farmers/respondents made their own decisions based on existing control techniques (30%) or depended on the decisions of pesticide vendors (29%). As for the pest forecasting method, it was mainly conducted by the Rural Development Administration affiliated organization (29%) and the National Crop Pest Management System (27%). Regarding the reliability of the pest diagnosis and pesticide prescription of pesticide vendors, 97% of the respondents marked above average. However, there was no choice on strong reliability. Interestingly, 79% of the respondents agreed to train experts for pest diagnosis and pesticide prescription with high necessity and, in particular, 47% of respondents were very strongly supported. These results suggest that the farmers might be need more qualified experts in pest diagnosis and pesticide prescriptions. Taken together, these survey results would provide important information to understand the current status of pest management by farmers' point of view and useful to set the direction of pest control.

• Journal of the Korea Computer Graphics Society
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• v.27 no.5
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• pp.63-71
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• 2021

Among drone autonomous flight technologies, obstacle avoidance is a very important technology that can prevent damage to drones or surrounding environments and prevent danger. Although the LiDAR sensor-based obstacle avoidance method shows relatively high accuracy and is widely used in recent studies, it has disadvantages of high unit price and limited processing capacity for visual information. Therefore, this paper proposes an obstacle avoidance algorithm for drones using camera-based PPO(Proximal Policy Optimization) reinforcement learning, which is relatively inexpensive and highly scalable using visual information. Drone, obstacles, target points, etc. are randomly located in a learning environment in the three-dimensional space, stereo images are obtained using a Unity camera, and then YOLov4Tiny object detection is performed. Next, the distance between the drone and the detected object is measured through triangulation of the stereo camera. Based on this distance, the presence or absence of obstacles is determined. Penalties are set if they are obstacles and rewards are given if they are target points. The experimennt of this method shows that a camera-based obstacle avoidance algorithm can be a sufficiently similar level of accuracy and average target point arrival time compared to a LiDAR-based obstacle avoidance algorithm, so it is highly likely to be used.

• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.67-75
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• 2022

The purpose of this study is to present an appropriate management plan as a supplement to the scientific evidence of the currently operated distancing system for preventing COVID-19. The currently being used mathematical models are expressed as simultaneous ordinary differential equations, there is a problem in that it is difficult to use them for the management of entry and exit of small business owners. In order to supplement this point, in this paper, a method for quantitatively expressing the risk of infection by people who gather is presented in consideration of the allowable risk given to the gathering space, the basic infection reproduction index, and the risk reduction rate due to vaccination. A simple quantitative model was developed that manages the probability of infection in a probabilistic level according to a set of visitors by considering both the degree of infection risk according to the vaccination status (non-vaccinated, primary inoculation, and complete vaccination) and the epidemic status of the virus. In a given example using the model, the risk was reduced to 55% when 20% of non-vaccinated people were converted to full vaccination. It was suggested that management in terms of quarantine can obtain a greater effect than medical treatment. Based on this, a generalized model that can be applied to various situations in consideration of the type of vaccination and the degree of occurrence of confirmed cases was also presented. This model can be used to manage the total risk of people gathered at a certain space in a real time, by calculating individual risk according to the type of vaccine, the degree of inoculation, and the lapse of time after inoculation.

• Journal of the Korean Society for Library and Information Science
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• v.56 no.3
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• pp.241-264
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• 2022

Bibliographic metadata can help researchers effectively utilize essential publications that they need and grasp academic trends of their own fields. With the manual creation of the metadata costly and time-consuming. it is nontrivial to effectively automatize the metadata construction using rule-based methods due to the immoderate variety of the article forms and styles according to publishers and academic societies. Therefore, this study proposes a two-step extraction process based on rules and deep neural networks for generating bibliographic metadata of scientific articlles to overcome the difficulties above. The extraction target areas in articles were identified by using a deep neural network-based model, and then the details in the areas were analyzed and sub-divided into relevant metadata elements. IThe proposed model also includes a model for generating reference summary information, which is able to separate the end of the text and the starting point of a reference, and to extract individual references by essential rule set, and to identify all the bibliographic items in each reference by a deep neural network. In addition, in order to confirm the possibility of a model that generates the bibliographic information of academic papers without pre- and post-processing, we conducted an in-depth comparative experiment with various settings and configurations. As a result of the experiment, the method proposed in this paper showed higher performance.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.340-350
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• 2021

This study was conducted by utilizing the Q research method, which is one of the qualitative analysis methods that can approach the in-depth and essential meaning of consumers' restaurant O2O service operation behavior. The purpose of this study is to classify the behavior of restaurant O2O services by type, to find out the characteristics of variables, and to suggest future improvement directions. An exploratory study was conducted using the Q-methodology to analyze the subjective perception of the restaurant O2O service behavior. To this end, positive and negative statement cards were prepared, P samples were selected, and Q-sort, which was subjected to classification, was analyzed using the PC QUANL program and Q factor analysis. As a result of the analysis, it was classified into three single types. Type 1 【(N= 7: Restaurant O2O Service Convenience Syndrome Type】, Type 2 【(N= 7): Restaurant O2O Service Benefit Pursuit Type】, Type 3 【(N= 6): Restaurant O2O Service Convenience Type】 The name of the factor was set as [Type], and it was found that each type has different characteristics. Through this analysis, the marketing strategy according to each factor detected is presented, and the point of supplementing the restaurant's O2O service and the direction of future operation. services in future studies.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.2
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• pp.29-42
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• 2022

The government promotes the 2050 carbon-neutral policy. Therefore, the concern to convert livestock manure into energy is increasing for the reduction of greenhouse gases generated in the livestock industry sector. In this study, the economic feasibility of the livestock manure solid fuel power generation facility, which is a major consumer of livestock manure solid fuel, was assessed to expand the demand for livestock manure solid fuel. The production cost of livestock manure solid fuel showed the lowest production cost of 97.4 thousand won/ton when dried using solid fuel at a 200 ton/day scale bio-drying facility. The livestock manure solid fuel power generation facility showed economic feasibility at a REC weight of 1.5 in the case of the bio-drying facility, so it was necessary to set a REC weight of 1.5 or more to expand the demand for livestock manure solid fuel. The conversion of livestock manure into solid fuel has various environmental benefits, such as the reduction of greenhouse gases and the effect of reducing non-point pollutants in the water system. Therefore, in order to expand livestock manure solid fuel production facility, it was required to review the feasibility including various environmental benefits.

• Journal of Internet of Things and Convergence
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• v.8 no.3
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• pp.11-20
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• 2022

Corporations operate within long term strategy. The Chief Executive Officer (CEO) makes decisions and has responsibility for all executive activities which affects the corporate performance. If the CEO makes strategic choices through reasonable decision making, it could affect corporate performance and corporate's rise and fall. So the CEO's decision making is very important. As rapid change in the digital technology environment happened, through digital transition, corporations have been working on increasing corporate performance by practical and academic methods. However prior research was restricted to CEO's affect on organization, innovation or innovative activities and there is a lack of research linking CEO's characteristics to digital transition and corporate performance. As the digital age is coming, research on how CEO's characteristics affect digital transition and corporate performance is direly needed. From the case of domestic Big Data corporation RSN Co. ltd's digital transition success, understanding characteristics of CEO, digital transition and corporate performance through prior researches, and developing research model and research proposition was set. Research was performed on RSN co. ltd's case analysis, and how characteristics of CEO's matter on digital transformation and corporate performance. As a result of the proposition, when the CEO conjugates digital technology, the corporation was able to successfully complete digital transition and it also affects corporate performance. Also, this research's other point is that CEO's may have limits on thoughtful decision making. It is judged that it is necessary to try an empirical study in the future.