• 레미콘
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• no.7 s.68
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• pp.9-16
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• 2001

Execution of exposed concrete has some problems such as segregation, surface honey comb and insufficient surface flossing due to unsuitable mix proportion and unfavorable construction in our field. Therefore, in this paper, field application of exposed concrete at training center building of Chongju university in Daecheon are carried out based on the mixing data obtained from laboratory test. Base concrete are made in accordance with mixing data. Segregation reducing type superplasticizer developed are applied in order to flow the vase concrete with out segregation of materials. According to test results, air content shows to be reduced after flowing. Compressive strength of flowing concrete is higher than that of base concrete about 7%. Surface glossing is reducing as the age goes on. It is improved about 10% compared to that of vase concrete.

• Korea Journal of Hospital Management
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• v.14 no.2
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• pp.75-98
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• 2009

As the organizational environments are changing, organizational innovation has become a critical success factor for the healthcare organizations. Although there are lots of successful innovation cases in other industries, healthcare organization's management innovation cases are rare in Korea. This case study is focused on successful change process of a Maeumsarang psychiatric hospital. Main findings are: (a) virtuous cycle of healthcare service innovation and organizational innovation, (b) intensive training and learning, (c) usage of external resources, (d) high commitment HRM system, (e) CEO leadership, and (f) synchronization of planning and execution. Based on these findings, managerial implications are derived and future research directions are proposed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.853-873
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• 2021

In recent years, deep reinforcement learning (DRL) models are enjoying great interest as their success in a variety of challenging tasks. Deep Q-Network (DQN) is a widely used deep reinforcement learning model, which trains an intelligent agent that executes optimal actions while interacting with an environment. This model is well known for its ability to surpass skilled human players across many Atari 2600 games. Although DQN has achieved excellent performance in practice, there lacks a clear understanding of why the model works. In this paper, we present a visual analytics system for understanding deep Q-network in a non-blind matter. Based on the stored data generated from the training and testing process, four coordinated views are designed to expose the internal execution mechanism of DQN from different perspectives. We report the system performance and demonstrate its effectiveness through two case studies. By using our system, users can learn the relationship between states and Q-values, the function of convolutional layers, the strategies learned by DQN and the rationality of decisions made by the agent.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.447-450
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• 2021

시뮬레이션을 비롯한 많은 다중 에이전트 환경에서는 중앙 집중 훈련 및 분산 수행(centralized training with decentralized execution; CTDE) 방식이 활용되고 있다. CTDE 방식 하에서 중앙 집중 훈련 및 분산 수행 환경에서의 다중 에이전트 학습을 위한 상태 행동 가치 기반(state-action value; Q-value) 다중 에이전트 알고리즘들에 대한 많은 연구가 이루어졌다. 이러한 알고리즘들은 Independent Q-learning (IQL)이라는 강력한 벤치 마크 알고리즘에서 파생되어 다중 에이전트의 공동의 상태 행동 가치의 분해(Decomposition) 문제에 대해 집중적으로 연구되었다. 본 논문에서는 앞선 연구들에 관한 알고리즘들에 대한 분석과 실용적이고 일반적인 도메인에서의 실험 분석을 통해 검증한다.

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.55-64
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• 2010

This paper proposes a face detection method using Free Rectangle feature which possesses a quick execution time and a high efficiency. The proposed mask of Free Rectangle feature is composed of two separable rectangles with the same area. In order to increase the feature diversity, Haar-like feature generally uses a complex mask composed of two or more rectangles. But the proposed feature mask can get a lot of very efficient features according to any position and scale of two rectangles on the feature window. Moreover, the Free Rectangle feature can largely reduce the execution time since it is defined as the only difference of the sum of pixels of two rectangles irrespective of the mask type. Since it yields a quick detection speed and good detection rates on real world images, the proposed face detection method based on Adaboost algorithm is easily applied to detect another object by changing the training dataset.

• Journal of Korea Multimedia Society
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• v.24 no.7
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• pp.890-902
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• 2021

Although the object detection accuracy with still images has been significantly improved with the advance of deep learning techniques, the object detection problem with video data remains as a challenging problem due to the real-time requirement and accuracy drop with occlusion. In this research, we propose a method in pig detection for video monitoring environment. First, we determine a motion, from a video data obtained from a tilted-down-view camera, based on the average size of each pig at each location with the training data, and extract key frames based on the motion information. For each key frame, we then apply YOLO, which is known to have a superior trade-off between accuracy and execution speed among many deep learning-based object detectors, in order to get pig's bounding boxes. Finally, we merge the bounding boxes between consecutive key frames in order to reduce false positive and negative cases. Based on the experiment results with a video data set obtained from a pig farm, we confirmed that the pigs could be detected with an accuracy of 97% at a processing speed of 37fps.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.730-739
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• 2016

The purpose of this study is to find improvements in current issues faced in counseling training within the military and also show limits in counseling capabilities of military officers who are in charge of leading and counseling their troops. In reference to previous studies made on this topic, we looked at issues rising from military troops who are mainly in their post-adolescents having difficulties in adopting themselves to military life style. We also studied current status of counseling within the military and the counseling difficulties faced by military officers who are closely related to their troops.Survey and in-depth interviews were conducted to achieve the purpose of this study. 100 military officers were surveyed for the frequency of the counseling sessions, and to supplement the survey, in-depth interviews were conducted 3 military officers and analyzed qualitatively. As a result of the survey and the in-depth interviews 76.5% of the military officers never had counseling training prior to joining the military and only 32.9% received counseling training after joining the military. 61% of the survey participants expressed difficulties in counseling their troops. Most of them expressed difficulties in lack of training and issues on theory based training. For the improvements following have been identified; "understanding the troops", "Identifying the problems", "Execution of the training" and "Techniques for Military Training". This study has a meaning in terms of identifying improvement areas in counseling training in the military through researching into current limits in military counseling and military officers counseling capabilities when the social issue of new troops having difficulties in adopting to military life style are on the rise.

• Journal of The Korean Association For Science Education
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• v.42 no.4
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• pp.429-438
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• 2022

In this study, we propose a way to improve science teacher expertise through infographics creation teacher training program by analyzing the infographics types focusing on the Earth Science subject of the 2015 revised curriculum, and inspecting the teachers' utilization of graphic tools. The data visualization characteristics of Earth Science textbooks were analyzed, the execution results of the infographics creation teacher training program were presented, and a survey on science teachers' change in perception and competency of infographics. As a result of the Earth Science textbook analysis, diagram-type, map-type, and comparative analysis-type infographics were frequently used, and were mainly presented as text-assisted-type infographics. The infographics creation teacher training program was conducted five times for 112 science teachers to create the complete, text-assisted, incomplete, and gradient-type infographics. Incomplete infographics for development of evaluation questions were most needed. Although many science teachers recognize the importance of infographics, they lacked the competency to create high-quality infographics because there were no training opportunities for infographics creation. After completing the training, 74.1% of teachers felt that the quality of developments of supplementary textbooks and evaluation questions had improved, and answered that it was helpful in re-educating knowledge and improving teaching-learning methods. Based on the research results, ways to improve science teacher expertise through infographics creation teacher training program were suggested.

• KIISE Transactions on Computing Practices
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• v.21 no.3
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• pp.167-172
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• 2015

Machine learning is a technique for training computers to be used in classification or forecasting. Among the various types, support vector machine (SVM) is a fast and reliable machine learning mechanism. In this paper, we evaluate the stock price predictability of SVM based on financial statements, through a fundamental analysis predicting the stock price from the corporate intrinsic values. Corporate financial statements were used as the input for SVM. Based on the results, the rise or drop of the stock was predicted. The SVM results were compared with the forecasts of experts, as well as other machine learning methods such as ANN, decision tree and AdaBoost. SVM showed good predictive power while requiring less execution time than the other machine learning schemes.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.35-42
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• 2014

It is possible to improve the obstacle avoidance capability by training and recognizing the obstacles which is in certain indoor environment. We propose the technique that use underlying intensity value along with intensity map from RGB-D image which is derived from stereo vision Kinect sensor and recognize an obstacle within constant distance. We test and experiment the accuracy and execution time of the pattern recognition algorithms like PCA, ICA, LDA, SVM to show the recognition possibility of it. From the comparison experiment between RGB-D data and intensity data, RGB-D data got 4.2% better accuracy rate than intensity data but intensity data got 29% and 31% faster than RGB-D in terms of training time and intensity data got 70% and 33% faster than RGB-D in terms of testing time for LDA and SVM, respectively. So, LDA, SVM have good accuracy and better training/testing time to use for obstacle avoidance based on intensity dataset of mobile robot.