• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.449-454
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• 2020

This paper proposes a machine learning-based emotion analysis system that detects a user's depression through their SNS posts. We first made a list of keywords related to depression in Korean, then used these to create a training data by crawling Twitter data - 1,297 positive and 1,032 negative tweets in total. Lastly, to identify the best machine learning model for text-based depression detection purposes, we compared RNN, LSTM, and GRU in terms of performance. Our experiment results verified that the GRU model had the accuracy of 92.2%, which is 2~4% higher than other models. We expect that the finding of this paper can be used to prevent depression by analyzing the users' SNS posts.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.2 s.42
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• pp.7-15
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• 2005

Numerical analysis model is proposed to predict the dynamic behavior of a single-degree-of-freedom structure that is equipped with hybrid base isolation system. Hybrid base isolation system is composed of friction pendulum systems (FPS) and a magnetorheological (MR) damper. A neuro-fuzzy model is used to represent dynamic behavior of the MR damper. Fuzzy model of the MR damper is trained by ANFIS (Adaptive Neuro-Fuzzy Inference System) using various displacement, velocity, and voltage combinations that are obtained from a series of performance tests. Modelling of the FPS is carried out with a nonlinear analytical equation that is derived in this study and neuro-fuzzy training. Fuzzy logic controller is employed to control the command voltage that is sent to MR damper. The dynamic responses of experimental structure subjected to various earthquake excitations are compared with numerically simulated results using neuro-fuzzy modeling method. Numerical simulation using neuro-fuzzy models of the MR damper and FPS predict response of the hybrid base isolation system very well.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.75-82
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• 2005

The robust feature vector selection method for the multiple frontal face detection is proposed in this paper. The proposed feature vector for the training and classification are integrated by means, amplitude projections, and its 1D Harr wavelet of the input image. And the statistical modeling is performed both for face and nonface classes. Finally, the estimated probability density functions (PDFs) are applied for the detection of multiple frontal faces in the still image. The proposed method can handle multiple faces, partially occluded faces, and slightly posed-angle faces. And also the proposed method is very effective for low quality face images. Experimental results show that detection rate of the propose method is $98.3\%$ with three false detections on the testing data, SET3 which have 227 faces in 80 images.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.334-348
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• 2002

In this study we have developed programs to enhance the scientific creativity by reviewing literature on the creativity and analyzing the theoretical models related to gifted education. The scientific creativity is regarded as the process of problem solving and problem finding, in particular, solving and finding the ill-defined but significant problems. In general, the important components of the scientific creativity are considered as the scientific knowledge, process skill, divergent/critical thinking, ill-defined problem, and problem finding. The program developed for the purpose of the study is composed of three stages based on Renzulli's model : general exploratory activities, group training activities and individual and small group investigations of real problems. The developed program in this study consists of 4 themes, 15 school hours in the earth science area. The process and products of the program development as well as the background of the present research are described and discussed in detail.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.419-429
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• 1999

Identifying the boundary of the effective receiving power of waves is one of the most important factors for cell optimization. In this paper, we introduce a propagation loss prediction model which yields highly accurate prediction in very complex areas as Seoul where a mixture of many large buildings, small buildings, broad streets, narrow alleys, rivers and forests co-exist in an irregular arrangement. This prediction model is based on neural networks trained on field measurement data collected in the past. Using these data along with 3-D digital elevation maps and vector data for building structures, we extract the parameter values which mainly affect the amount of propagation loss. These parameter values are then used as the inputs to the neural network. Trained neural network becomes the approximated function of the propagation loss model which generalizes very well and can predict accurately in the regions not included in training the neural network. The experimental results show a superior performance over the other models in the cells operating in the city of Seoul.

• The Journal of Korean Academic Society of Nursing Education
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• v.26 no.4
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• pp.337-347
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• 2020

Purpose: The purpose of this study was to figure out the association of nursing activity participation and clinical practice stress with career maturity during clinical practice among nursing college students. Methods: Participants of the study were 201 nursing college students located in nationwide regions. Data collection was performed between July 18 and August 8, 2019. Data analyses were performed through an independent t-test, ANOVA, Pearson's correlation coefficient, and multiple linear regression analysis using SPSS WIN 25.0. Results: The results of this study were as follows. We ran multiple regression analyses to see which critical factors influenced career maturity. The general characteristics significantly associated with career maturity were preference for clinical nursing, admission to nursing college due to belief, time off, and being satisfied with clinical practice. Regarding clinical practice stress, clinic environment, interpersonal relationship conflict, inappropriate role model and conflict with patients were significantly associated with career maturity. Conclusion: This study suggested that, to improve nursing students' career maturity, nursing colleges and training fields should collaboratively make an efforts to reduce students' stress by building educational clinic environments including managing conflicts in interpersonal relationships among patients, caregivers, and medical and non-medical personnel, and improving inappropriate role models in nursing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.2946-2952
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• 2014

Among the Example based Super Resolution(SR) techniques, Neighbor embedding(NE) has been inspired by manifold learning method, particularly locally linear embedding. However, the poor generalization of NE decreases the performance of such algorithm. The sizes of local training sets are always too small to improve the performance of NE. We propose the Learning Sparse-Neighbor Image Representation baesd on SVR having an excellent generalization ability to solve this problem. Given a low resolution image, we first use bicubic interpolation to synthesize its high resolution version. We extract the patches from this synthesized image and determine whether each patch corresponds to regions with high or low spatial frequencies. After the weight of each patch is obtained by our method, we used to learn separate SVR models. Finally, we update the pixel values using the previously learned SVRs. Through experimental results, we quantitatively and qualitatively confirm the improved results of the proposed algorithm when comparing with conventional interpolation methods and NE.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.500-509
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• 2009

Passive samplers have been used for many years for the sampling of organic vapors in work environment atmospheres. Currently, all passive samplers used in domestic occupational monitoring are foreign products. This study was performed to evaluate variable parameters for the development of passive organic samplers, which include the geometry of the device and diffusive length for the sampler design. Four prototype diffusive lengths; A-1(4.5 mm), A-2(7.0 mm), A-3(9.5 mm), A-4(12.0 mm) were tested for adsorption performances to a chemical mixture (benzene, toluene, trichloroethylene, and n-hexane) according to the US-OSHA's evaluation protocol. A dynamic vapor exposure chamber developed and verified by related research was used for this study. The results of study are as follows. The results in terms of sampling rate and recommended sampling time test indicate that the most suitable model was A-3 (9.5 mm diffusive lengths on both sides) for passive sampler design in time weighted average (TWA) assessment. Sampling rates of this A-3 model were 45.8, 41.5, 41.4, and 40.3 ml/min for benzene, toluene, trichloroethylene, and n-hexane, respectively. The A-3 models were tested on reverse diffusion and conditions of low humidity air (35% RH) and low concentrations (0.2 times of TLV). These conditions had no affect on the diffusion capacity of samplers. In conclusion, the most suitable design parameters of passive sampler are: 1) Geometry and structure - 25 mm diameter and 490 $mm^2$ cross sectional area of diffusion face with cylindrical form of two-sided opposite diffusion direction; 2) Diffusive length - 9.5 mm in both faces; 3) Amount of adsorbent - 300 mg of coconut shell charcoal; 4) Wind screen - using nylon net filters (11 ${\mu}m$ pore size).

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.272-284
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• 1996

The present study has quantitatively assessed the regional production, income and employment impact resulting from the construction and operation of nuclear power plant (NPP) upon the domestic local areas by applying the regional input-output analysis model to the case of Wolsong unit-l site. The conclusions regarding the most likely regional economic impacts upon the wolsong site are summarized as follows: 1. The income multipliers are calculated to be 1.563 for the construction phase and 1.500 for the operation phase. These values are relatively high compared with those of other conventional facilities. 2. The level of total employee's wage induced employment associated with the construction phase has been estimated to be 37,000 while that with the operational phase in 1990 to be 5,610. 3. With relation to the aspect of resident welfare it is found that the industrial sector associated with electricity, gas and water supply have remarkably improved with the construction of the NPP. 4. The NPP siting has induced substantial changes in interindustry (input-output) structures of the Wolsong unit-l site which is one of the rural areas where all the domestic NPPs are sited. Such changes are attributed to the industrial recomposition of the region. 5. With the application of other regional economic analysis models and the use of more sufficient regional data, other detailed studies on the economic impact analysis of domestic NPP-related facility sitings are suggested to be carried out further since the influence of NPP sitings is significant to the national economic impact as well as the regional economic impact.

• Biomaterials and Biomechanics in Bioengineering
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• v.3 no.1
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• pp.15-26
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• 2016

Based on a survey done recently in Japan, 30 percent of the serious accidents occurred in oral implant surgery were concerned with the mandibular canal and 3/4 of them were related to drilling. One of the reasons lies in the lack of the education system. To overcome this problem, a new educational system focusing on drilling the mandibular trabecular bone has been developed mainly for dental college students in the form of an oral implant surgery training simulator that enables student to sense the reaction force during drilling. On the other hand, the conventional system uses polymeric model. Based on these systems, two approaches were proposed; the evaluation by experienced clinicians using the simulator, and experimental works on the polymeric model. Focusing on the combination of the drilling force sensed and drilling speed obtained through both approaches, the results were compared. It was found that the polymeric models were much softer especially near the mandibular canal. In addition, the study gave us an insight of the understanding in bone quality through tactile sensation of the drilling force and speed. Furthermore, the clinicians positively reviewed the simulator as a valid tool.