• Title/Summary/Keyword: 샘플링 전략

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Leision Detection in Chest X-ray Images based on Coreset of Patch Feature (패치 특징 코어세트 기반의 흉부 X-Ray 영상에서의 병변 유무 감지)

  • Kim, Hyun-bin;Chun, Jun-Chul
    • Journal of Internet Computing and Services
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    • v.23 no.3
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    • pp.35-45
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    • 2022
  • Even in recent years, treatment of first-aid patients is still often delayed due to a shortage of medical resources in marginalized areas. Research on automating the analysis of medical data to solve the problems of inaccessibility for medical services and shortage of medical personnel is ongoing. Computer vision-based medical inspection automation requires a lot of cost in data collection and labeling for training purposes. These problems stand out in the works of classifying lesion that are rare, or pathological features and pathogenesis that are difficult to clearly define visually. Anomaly detection is attracting as a method that can significantly reduce the cost of data collection by adopting an unsupervised learning strategy. In this paper, we propose methods for detecting abnormal images on chest X-RAY images as follows based on existing anomaly detection techniques. (1) Normalize the brightness range of medical images resampled as optimal resolution. (2) Some feature vectors with high representative power are selected in set of patch features extracted as intermediate-level from lesion-free images. (3) Measure the difference from the feature vectors of lesion-free data selected based on the nearest neighbor search algorithm. The proposed system can simultaneously perform anomaly classification and localization for each image. In this paper, the anomaly detection performance of the proposed system for chest X-RAY images of PA projection is measured and presented by detailed conditions. We demonstrate effect of anomaly detection for medical images by showing 0.705 classification AUROC for random subset extracted from the PadChest dataset. The proposed system can be usefully used to improve the clinical diagnosis workflow of medical institutions, and can effectively support early diagnosis in medically poor area.

A Study on Management Strategies and Structural Relationships in the Restaurant Industry Using the Service Profit Chain (서비스이익사슬 모형을 적용한 외식업의 구조적 관계와 경영전략에 관한 연구: 직원과 고객을 중심으로)

  • Kim, Gi-Jin;Byun, Gwang-In
    • Culinary science and hospitality research
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    • v.18 no.5
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    • pp.63-79
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    • 2012
  • The purpose of this study is to empirically determine the structural relationship between employee constructs such as internal service quality, employee satisfaction, and organization commitment and customer constructs such as perceived value, customer satisfaction, and loyalty to suggest an effective business strategy for restaurant business. To do this, the study consulted with the Korea Restaurant Association, the representative of Korean food service and got the intention of participating in the research from the Daegu branch. As a result, 51 restaurants registered in the Daegu branch who showed their intention to participate were selected as an initial sample. Also, other restaurants were introduced through snow-ball sampling method by the owners of restaurants who finished responding to the survey, and total 100 restaurants were examined. A survey was conducted to external customers who visited restaurants and internal customers working there. For final analysis, 741 questionnaires of internal customers and 970 questionnaires of external customers were used. The result of analysis showed that team-work & communication in internal service quality has a significant effect on employee satisfaction, employee satisfaction on organization commitment, and organization commitment on value perceived by customers. Also, perceived value has a significant effect on customer satisfaction and loyalty, and customer satisfaction on loyalty.

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A Study on the Activation Plan for Professional Sport League through Exploration of Inducing Factors of Match Fixing (승부조작 유발요인 탐색을 통한 프로스포츠 활성화 방안)

  • Bang, Shin-Woong;Park, In-Sil;Kim, Wook-Ki
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.3
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    • pp.153-170
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    • 2021
  • This study was attempted to derive strategic implications for activating professional sports by conducting in-depth interviews with professional sports officials such as players, teams, federations, agencies, etc., by searching for factors that cause match fixing and deriving preventive strategies based on them. Eight people with more than 3 years of experience working in professional sports were selected using the snowball sampling technique. Data were collected and analyzed by applying a semi-structured in-depth interview method for them. As a result of the analysis, five core categories (the learning effect from the cartel for entering university, the culture learned in a camp training, the manifestation of the latent learning effect, the negative effect of the human network, the personal disposition) were derived as factors causing match-fixing. As for the strategy to prevent match fixing, first, improving the college entrance examination system oriented on individual capability, second, improving the education system for student athlete, third, establishing a prevention system, fourth, continuing education, fifth, and activating the agent system as the core categories. Implications for the derived research results and future research directions were discussed.

The Development of Intervention Program for Enhancing Elementary Science-Poor Students' Basic Science Process Skills - Focus on Eye Movement Analysis - (초등과학부진학생의 기초과학탐구능력 향상을 위한 중재프로그램 개발 -안구운동을 중심으로-)

  • Shin, Won-Sub;Shin, Dong-Hoon
    • Journal of The Korean Association For Science Education
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    • v.34 no.8
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    • pp.795-806
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    • 2014
  • The purpose of this study is to develop an intervention program for improvement of elementary science-poor students' Basic Science Process Skill (BSPS) and to validate the intervention program's effectiveness using eye-tracker. The participants of this study were 35 elementary science-poor students. This study's method was the analysis of real-time eye movements during basic science process skill problem solving. SMI's 120 Hz iView XTM RED was used to collect EMD (eye movement data). Experiment 3.4 and BeGaze 3.4 programs were used to design experiment and to analyze EMD. The results of this study are as follows. First, we developed an intervention program including BSPS instructional strategy, behavior of teachers & student according instructional strategy stage, teachinglearning plan and learning note. Second, science poor students' BSPS ability has improved statistically significantly through the application of intervention program and BSPS problem-solving time decreased statistically significantly. Third, AFT (average fixation time) of BSPS Question and keyword area decreased statistically significantly. Fourth, APD (average pupil diameter) of BSPS problem-solving process expanded statistically significantly. Fifth, AST (average saccade time) of BSPS problem-solving process increased statistically significantly. Sixth, AFET (average fixation entry time) of BSPS problem-clue area was accelerated statistically significantly, AFT of BSPS problem-clue area reduced statistically significantly.

A Study of Establishment and application Algorithm of Artificial Intelligence Training Data on Land use/cover Using Aerial Photograph and Satellite Images (항공 및 위성영상을 활용한 토지피복 관련 인공지능 학습 데이터 구축 및 알고리즘 적용 연구)

  • Lee, Seong-hyeok;Lee, Moung-jin
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.871-884
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    • 2021
  • The purpose of this study was to determine ways to increase efficiency in constructing and verifying artificial intelligence learning data on land cover using aerial and satellite images, and in applying the data to AI learning algorithms. To this end, multi-resolution datasets of 0.51 m and 10 m each for 8 categories of land cover were constructed using high-resolution aerial images and satellite images obtained from Sentinel-2 satellites. Furthermore, fine data (a total of 17,000 pieces) and coarse data (a total of 33,000 pieces) were simultaneously constructed to achieve the following two goals: precise detection of land cover changes and the establishment of large-scale learning datasets. To secure the accuracy of the learning data, the verification was performed in three steps, which included data refining, annotation, and sampling. The learning data that wasfinally verified was applied to the semantic segmentation algorithms U-Net and DeeplabV3+, and the results were analyzed. Based on the analysis, the average accuracy for land cover based on aerial imagery was 77.8% for U-Net and 76.3% for Deeplab V3+, while for land cover based on satellite imagery it was 91.4% for U-Net and 85.8% for Deeplab V3+. The artificial intelligence learning datasets on land cover constructed using high-resolution aerial and satellite images in this study can be used as reference data to help classify land cover and identify relevant changes. Therefore, it is expected that this study's findings can be used in the future in various fields of artificial intelligence studying land cover in constructing an artificial intelligence learning dataset on land cover of the whole of Korea.

Development of Sauces Made from Gochujang Using the Quality Function Deployment Method: Focused on U.S. and Chinese Markets (품질기능전개(Quality Function Deployment) 방법을 적용한 고추장 소스 콘셉트 개발: 미국과 중국 시장을 중심으로)

  • Lee, Seul Ki;Kim, A Young;Hong, Sang Pil;Lee, Seung Je;Lee, Min A
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.9
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    • pp.1388-1398
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    • 2015
  • Quality Function Deployment (QFD) is the most complete and comprehensive method for translating what customers need from a product. This study utilized QFD to develop sauces made from Gochujang and to determine how to fulfill international customers' requirements. A customer survey and expert opinion survey were conducted from May 13 to August 22, 2014 and targeted 220 consumers and 20 experts in the U.S. and China. Finally, a total of 208 (190 consumers and 18 experts) useable data were selected. The top three customer requirements for Gochujang sauces were identified as fresh flavor (4.40), making better flavor (3.99), and cooking availability (3.90). Thirty-three engineering characteristics were developed. The results from the calculation of relative importance of engineering characteristics identified that 'cooking availability', 'free sample and food testing', 'unique concept', and 'development of brand' were the highest. The relative importance of engineering characteristics, correlation, and technical difficulties are ranked, and this result could contribute to the development Korean sauces based on customer needs and engineering characteristics.

An Analysis of Elementary Students' Attention Characteristics through Attention Test and the Eye Tracking on Real Science Classes (실제 과학수업에서 시선추적과 주의력 검사를 통한 초등학생들의 주의 특성 분석)

  • Shin, Won-Sub;Shin, Dong-Hoon
    • Journal of The Korean Association For Science Education
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    • v.36 no.4
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    • pp.705-715
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    • 2016
  • The purpose of this research is to analyze elementary students' attention characteristics through attention test and eye tracking on real science classes. The SMI's ETG(eye tracker glasses) mobile eye tracker was used to analyze the attention process of elementary students'. The sampling rate of the ETG is 30Hz. The participants of attention test were elementary 155 6th-grade elementary students and the participants for the eye-tracker were six 6th-grade male students. The eye movements were analyzed using the 'BeGaze Mobile Video Analysis Package' program. The results of this research are as follows. First, the attention test results of elementary students showed high correlation between selective attention and sustained attention (.85) and low correlation between selective attention and self-regulation (.32). Second, the attention types of elementary students were divided into four; attention, inattention, easygoing and hasty. Third, elementary students' attention were divided into top-down, bottom-up, default mode network through analysis of elementary students′ eye-movements during real science classes. Also their attention shift occurred frequently due to various reasons in real class situation. There were three reasons that made elementary students fail to handle knowledge-dependent top-down attention; 1) the cognitive failure of target caused by failing to focus attention, 2) the absence of prior knowledge on target object, 3) the analogical failure of prior knowledge. Finally, elementary students' attention process were schematized based on the analysis of students' eye movements and attention test. This research is expected to be utilized as basic data for developing effective teaching strategies, teaching-learning models and instructional materials.

Evaluating Reverse Logistics Networks with Centralized Centers : Hybrid Genetic Algorithm Approach (집중형센터를 가진 역물류네트워크 평가 : 혼합형 유전알고리즘 접근법)

  • Yun, YoungSu
    • Journal of Intelligence and Information Systems
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    • v.19 no.4
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    • pp.55-79
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    • 2013
  • In this paper, we propose a hybrid genetic algorithm (HGA) approach to effectively solve the reverse logistics network with centralized centers (RLNCC). For the proposed HGA approach, genetic algorithm (GA) is used as a main algorithm. For implementing GA, a new bit-string representation scheme using 0 and 1 values is suggested, which can easily make initial population of GA. As genetic operators, the elitist strategy in enlarged sampling space developed by Gen and Chang (1997), a new two-point crossover operator, and a new random mutation operator are used for selection, crossover and mutation, respectively. For hybrid concept of GA, an iterative hill climbing method (IHCM) developed by Michalewicz (1994) is inserted into HGA search loop. The IHCM is one of local search techniques and precisely explores the space converged by GA search. The RLNCC is composed of collection centers, remanufacturing centers, redistribution centers, and secondary markets in reverse logistics networks. Of the centers and secondary markets, only one collection center, remanufacturing center, redistribution center, and secondary market should be opened in reverse logistics networks. Some assumptions are considered for effectively implementing the RLNCC The RLNCC is represented by a mixed integer programming (MIP) model using indexes, parameters and decision variables. The objective function of the MIP model is to minimize the total cost which is consisted of transportation cost, fixed cost, and handling cost. The transportation cost is obtained by transporting the returned products between each centers and secondary markets. The fixed cost is calculated by opening or closing decision at each center and secondary markets. That is, if there are three collection centers (the opening costs of collection center 1 2, and 3 are 10.5, 12.1, 8.9, respectively), and the collection center 1 is opened and the remainders are all closed, then the fixed cost is 10.5. The handling cost means the cost of treating the products returned from customers at each center and secondary markets which are opened at each RLNCC stage. The RLNCC is solved by the proposed HGA approach. In numerical experiment, the proposed HGA and a conventional competing approach is compared with each other using various measures of performance. For the conventional competing approach, the GA approach by Yun (2013) is used. The GA approach has not any local search technique such as the IHCM proposed the HGA approach. As measures of performance, CPU time, optimal solution, and optimal setting are used. Two types of the RLNCC with different numbers of customers, collection centers, remanufacturing centers, redistribution centers and secondary markets are presented for comparing the performances of the HGA and GA approaches. The MIP models using the two types of the RLNCC are programmed by Visual Basic Version 6.0, and the computer implementing environment is the IBM compatible PC with 3.06Ghz CPU speed and 1GB RAM on Windows XP. The parameters used in the HGA and GA approaches are that the total number of generations is 10,000, population size 20, crossover rate 0.5, mutation rate 0.1, and the search range for the IHCM is 2.0. Total 20 iterations are made for eliminating the randomness of the searches of the HGA and GA approaches. With performance comparisons, network representations by opening/closing decision, and convergence processes using two types of the RLNCCs, the experimental result shows that the HGA has significantly better performance in terms of the optimal solution than the GA, though the GA is slightly quicker than the HGA in terms of the CPU time. Finally, it has been proved that the proposed HGA approach is more efficient than conventional GA approach in two types of the RLNCC since the former has a GA search process as well as a local search process for additional search scheme, while the latter has a GA search process alone. For a future study, much more large-sized RLNCCs will be tested for robustness of our approach.