• Title/Summary/Keyword: problem analysis

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A Study on improvement of communication error between controllers for K56 ammunition transport vehicle (K56 탄약운반장갑차용 제어기 간 통신 오류 개선에 관한 연구)

  • Park, Joo-Young;Kim, Seong-Hoon;Noh, Sang-Wan;Park, Young-Min;Kim, Kyung-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.781-788
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    • 2021
  • This paper is the study of a design to eliminate the communication error that occurs between the main controller and the servo controller of the K56 ammunition-carrying armored vehicle. The K56 assists in the operation of the K-55A1 self-propelled gun by automating the supply and loading of ammunition. The CAN communication board of the ammunition carrier is a key-function product mounted inside the main controller and installed for communication with the servo controller. It was confirmed that an undefined error would occur intermittently in the existing CAN communication board, interrupting the operation of the ammunition supply system during the loading process. In this paper, in order to solve the problem, the cause of the failure is identified through analysis and a functional test of the communication signal between the main controller and the servo controller. The error was resolved by redesigning and improving the Read/Write algorithm. Finally, the proposed cause analysis and design effectiveness were verified through the CAN communication board single item test and a system equipment application test. It is expected that this study will serve as a reference for improving defense capabilities through improving the reliability of CAN communication boards and by improving the reliability of the overall electronic equipment using DPRAM.

LMU Design Optimization for the Float-Over Installation of Floating Offshore Platforms (부유식 해양구조물의 플로트오버 설치용 LMU 최적설계)

  • Kim, Hyun-Seok;Park, Byoungjae;Sung, Hong Gun;Lee, Kangsu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.1
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    • pp.43-50
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    • 2021
  • A Leg Mating Unit (LMU) is a device utilized during the float-over installation of offshore structures that include hyperelastic pads and mating part. The hyperelastic pads absorb the loads, whereas the mating part works as guidance between topside and supporting structures during the mating sequence of float-over installation. In this study, the design optimization of an LMU for the float-over installation of floating-type offshore structures is conducted to enhance the performance and to satisfy the requirements defined by classification society regulations. The initial dimensions of the LMU are referred to the dimensions of those used in fixed-type float-over installation because only the location and the number of LMUs are known. The two-parameter Mooney-Rivlin model is adopted to describe the hyperelastic pads under given material parameters. Geometric variables, such as the thickness, height, and width of members, as well as configuration variables, such as the angle and number of members, are defined as design variables and are parameterized. A sampling-based design sensitivity analysis based on latin hypercube sampling method is performed to filter the important design variables. The design optimization problem is formulated to minimize the total mass of the LMU under maximum von Mises stress and reaction force constraints.

Analysis of Spatial Characteristics of Vacant Houses using Geographic Weighted Regression Model - Focus on Busan Metropolitan City - (지리가중회귀모델을 적용한 빈집 발생의 공간적 특성 분석 - 부산광역시를 대상으로 -)

  • KIM, Ji-Yun;KIM, Ho-Yong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.1
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    • pp.68-79
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    • 2021
  • The recent occurrence of vacant houses in urban areas is a remarkable social problem. One of the physical declines, the occurrence of vacant houses, accelerates various social and economic declines, such as a decline in population and a slump in the commercial district. Vacant houses have regional characteristics and spatial influence, and it is necessary to approach them locally in order to grasp the exact status of vacant houses. Therefore, in this study, the effect of urban decline on the occurrence of vacant homes was examined by region using global Moran's I and Geographic Weighted Regression(GWR) model. As a result of the analysis, there were spatial autocorrelation and heterogeneity in the occurrence of vacant houses in each eup·myeon·dong, Busan metropolitan city. In addition, there is a difference in the influence of each variable of urban decline on the occurrence of vacant houses, and even the same variable of urban decline has different effects on the occurrence of vacant houses in different regions. Therefore, it is expected that a more efficient vacant home management plan can be presented if the GWR model is used to analyze the coefficient values differentiated by region and categorize the occurrence of vacant houses.

Development and analysis of assessment model of a village-level rural living services for response to rural depopulation (농촌 과소화 대응을 위한 마을 단위 농촌생활서비스 평가 모델의 개발 및 분석)

  • Hong, Sangwon;Bae, Seung-Jong;Kim, Dong-Hyeon;Kim, Soo-Jin;Kim, Jungtae;Jang, Taeil
    • Journal of Korean Society of Rural Planning
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    • v.27 no.1
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    • pp.57-70
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    • 2021
  • The degree of benefits of living services related to the quality of life can solve the depopulation problem, and it is necessary to be able to quantitatively analyze problems related to the quality of life in rural areas in order to cope with the rural depopulation. The purpose of this study was to develop the assessment model of a village-level rural living service that reflects the regional characteristics of rural villages to evaluate the level of rural living services for response rural depopulation. Based on the review of previous related studies, the evaluation index was composed of seven sectors of education, health, welfare, culture, environment, safety, and convenience, and the assessment model of a rural living service was established. This model was evaluated through a sample survey of 90 villages in Nonsan-si, Seongju-gun, and Pyeongchang-gun. As a result of the rural life services evaluation by Si and Gun, Seongju-gun, which is affected by nearby large cities, has the largest variation by village level and is assessed at a lower level overall than other Si and Gun. As a result of the rural life services evaluation by 7 sectors, in the case of health and welfare, low scores were shown in the assessment model, but the level of residents' satisfaction was mid-level. In particular, in the case of Seongju-gun, there were significant differences in the assessment model and the survey results of the level of residents' satisfaction in the health and welfare sectors due to the influence of nearby large cities. As a result of analyzing the number of villages corresponding to the top 30% and the bottom 30% of the evaluation results for each sector, it was analyzed that the villages with the highest evaluation results in Pyeongchang-gun in both the assessment model and the level of residents' satisfaction. It implies that quantitative analysis of data based index and accessibility as well as level satisfaction of residents are necessary.

Drought evaluation using unstructured data: a case study for Boryeong area (비정형 데이터를 활용한 가뭄평가 - 보령지역을 중심으로 -)

  • Jung, Jinhong;Park, Dong-Hyeok;Ahn, Jaehyun
    • Journal of Korea Water Resources Association
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    • v.53 no.12
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    • pp.1203-1210
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    • 2020
  • Drought is caused by a combination of various hydrological or meteorological factor, so it is difficult to accurately assess drought event, but various drought indices have been developed to interpret them quantitatively. However, the drought indexes currently being used are calculated from the lack of a single variable, which is a problem that does not accurately determine the drought event caused by complex causes. Shortage of a single variable may not be a drought, but it is judged to be a drought. On the other hand, research on developing indices using unstructured data, which is widely used in big data analysis, is being carried out in other fields and proven to be superior. Therefore, in this study, we intend to calculate the drought index by combining unstructured data (news data) with weather and hydrologic information (rainfall and dam inflow) that are being used for the existing drought index, and to evaluate the utilization of drought interpretation through verification of the calculated drought index. The Clayton Copula function was used to calculate the joint drought index, and the parameter estimation was used by the calibration method. The analysis showed that the drought index, which combines unstructured data, properly expresses the drought period compared to the existing drought index (SPI, SDI). In addition, ROC scores were calculated higher than existing drought indices, making them more useful in drought interpretation. The joint drought index calculated in this study is considered highly useful in that it complements the analytical limits of the existing single variable drought index and provides excellent utilization of the drought index using unstructured data.

Comparison of Antioxidant and Anti-inflammatory Activity of Korean Houttuynia cordata Thunb. Extracts (국내산 어성초(Houttuynia cordata Thunb.)추출물의 항산화 및 항염증 활성 비교)

  • Lim, Hyun-Ji;Lee, Hea-Jin;Lim, Mi-Hye
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.1
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    • pp.217-227
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    • 2021
  • In this study, Korean-cultivated Houttuynia cordata Thunb. (HC) was extracted anti-inflammatory effects of extracts were compared in order to confirm the possibility of natural cosmetics as a raw material. HPLC pattern analysis, cell viability assay, total phenolic contents, ABTS/DPPH radical scavenging analysis, measurement of ROS production, griess reagent assay, and luminex technique. The content of quercetin was higher in fresh Houttuynia cordata (HC-F) than in dried Houttuynia cordata (HC-D). Also, content of HC extracts shows a difference in the content of the two representative compounds (polyphenol and flavonoid) according to the stored differently. ROS production showed higher inhibitory rates at HC-F. The anti-inflammatory activity of HC-D was shown higher than that of HC-F. But, in the measurement of the reduction in inflammatory cytokines, IL-1β showed that HC-D had a relatively high reduction effect, and IL-6 and TNF-α showed a high reduction effect. And these results will be a basis for the development of cosmetology in skin care and improvement of skin problem.

Discussion and Analysis Study on the Introduction Plan of the Librarian Qualification System (사서자격인증제도의 도입방안에 관한 논의 및 분석연구)

  • Hong, Hyun-Jin;Noh, Younghee;Ro, Ji-Yoon
    • Journal of the Korean Society for Library and Information Science
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    • v.55 no.3
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    • pp.17-56
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    • 2021
  • The purpose of this study was to focus on the discussion on the introduction of the librarian qualification certification system, which is being discussed as a way to raise the qualification level of experts as a system for expert certification and to raise social awareness as experts. First, the introduction of the library and information science curriculum certification system was discussed. Second, the issues to be considered when introducing the certification system were discussed. In other words, we analyzed in depth what matters we should consider when discussing the certification system. Third, the components of domestic and overseas certification systems were investigated and analyzed, and measures applicable to the librarian qualification certification system were discussed. Fourth, it was proposed to introduce a certification system for the Department of Library and Information Science. Also, based on the results of the analysis, it was suggested what could be a problem when introducing the certification system to the Department of Library and Information Science in Korea and what contents should be reviewed. In this study, in order to propose the introduction of the librarian qualification certification system, the purpose of the librarian qualification certification system, the certification criteria, the certification institution, and the contrast between the university and the Department of Library and Information Science were also dealt with in detail.

A Movement Tracking Model for Non-Face-to-Face Excercise Contents (비대면 운동 콘텐츠를 위한 움직임 추적 모델)

  • Chung, Daniel;Cho, Mingu;Ko, Ilju
    • KIPS Transactions on Computer and Communication Systems
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    • v.10 no.6
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    • pp.181-190
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    • 2021
  • Sports activities conducted by multiple people are difficult to proceed in a situation where a widespread epidemic such as COVID-19 is spreading, and this causes a lack of physical activity in modern people. This problem can be overcome by using online exercise contents, but it is difficult to check detailed postures such as during face-to-face exercise. In this study, we present a model that detects posture and tracks movement using IT system for better non-face-to-face exercise content management. The proposed motion tracking model defines a body model with reference to motion analysis methods widely used in physical education and defines posture and movement accordingly. Using the proposed model, it is possible to recognize and analyze movements used in exercise, know the number of specific movements in the exercise program, and detect whether or not the exercise program is performed. In order to verify the validity of the proposed model, we implemented motion tracking and exercise program tracking programs using Azure Kinect DK, a markerless motion capture device. If the proposed motion tracking model is improved and the performance of the motion capture system is improved, more detailed motion analysis is possible and the number of types of motions can be increased.

Comparative Analysis of Anomaly Detection Models using AE and Suggestion of Criteria for Determining Outliers

  • Kang, Gun-Ha;Sohn, Jung-Mo;Sim, Gun-Wu
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.8
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    • pp.23-30
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    • 2021
  • In this study, we present a comparative analysis of major autoencoder(AE)-based anomaly detection methods for quality determination in the manufacturing process and a new anomaly discrimination criterion. Due to the characteristics of manufacturing site, anomalous instances are few and their types greatly vary. These properties degrade the performance of an AI-based anomaly detection model using the dataset for both normal and anomalous cases, and incur a lot of time and costs in obtaining additional data for performance improvement. To solve this problem, the studies on AE-based models such as AE and VAE are underway, which perform anomaly detection using only normal data. In this work, based on Convolutional AE, VAE, and Dilated VAE models, statistics on residual images, MSE, and information entropy were selected as outlier discriminant criteria to compare and analyze the performance of each model. In particular, the range value applied to the Convolutional AE model showed the best performance with AUC PRC 0.9570, F1 Score 0.8812 and AUC ROC 0.9548, accuracy 87.60%. This shows a performance improvement of an accuracy about 20%P(Percentage Point) compared to MSE, which was frequently used as a standard for determining outliers, and confirmed that model performance can be improved according to the criteria for determining outliers.

Acceptability Analysis for a Radio-Based Emergency Alert System at Access Zones of Freeway Tunnels Using a Structural Equation Modeling (구조방정식을 활용한 터널 진입부 라디오 재난경보방송 수용성 분석)

  • Kang, Chanmo;Chung, Younshik;Kim, Jong-Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.41 no.6
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    • pp.697-705
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    • 2021
  • Currently, roadway operation agencies provide interior zones of tunnels with emergency information including crash, fire, and vehicles' stop, through state-of-the-art technologies such as variable message signs and radio-based broadcast systems. However, when coping with an emergency in tunnel interior zones, such information could be too late for drivers to access. A radio-based emergency alert system at the access zones of freeway tunnels, on the other hand,could be a good alternative for solving this problem. Therefore, the objective of this study is to assess user acceptability of such an alternative system. To carry out this study, an online survey was conducted on 762 drivers, and the survey results were analyzed using a structural equation modeling to identify factors affecting acceptability of the proposed system. As a result, driver characteristics such as age group, driving frequency, and driving career, utilization of conventional traffic information, and usefulness of conventional traffic information have a positive impact on acceptability. It is expected that the findings of the study will be a basis to effectively address and deploy a new emergency alert system at the access zones of freeway tunnels.