• Title/Summary/Keyword: OBSTACLE

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Construction and Operation of Small Solar Plant Using Smart-Off-Grid: Case of Tanzania-Korea Innovative Technology and Energy Center (스마트-독립전력망을 사용한 소규모 태양광 발전소의 건설과 운영: 한국-탄자니아 적정기술 거점센터의 사례)

  • Kim, Jisoo;Jung, Woo-Kyun;Ha, Bo-Ra;Moon, Ji-Hyun;Rhee, Herb;Ahn, Sung-Hoon
    • Journal of Appropriate Technology
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    • v.5 no.2
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    • pp.62-69
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    • 2019
  • Supplying stable electric power is one of the important objectives of the Official Development Assistance (ODA) because it is strongly related with improving living standards and income levels in the region. However, rural areas in many developing countries are not properly connected to national power grids, and even areas connected to national power grids are frequently blacked out due to limitations in power capacity. These lack of electric power is a major obstacle to improving income levels and improving living standards in those areas. The Korea-Tanzania Innovative and Energy Center (iTEC), which was established by Seoul National University in cooperation with the Nelson-Mandela Africa Institute of Science and Technology and Technology (NM-AIST) try to build a small solar power plant using a smart-off grid in rural area of Tanzania, where there is no electricity. 10 kW and 7 kW solar power plants are built in Mkalama Village in Kilimanajaro Region and Ngurdoto Village in Arusha Region to provide power to about 50 households each. In addition, smart monitoring systems were installed to collect data about status of power system and power consumption of each house. iTEC seeks for sustainable improvement the income level and quality of life of rural residents in developing countries through the construction of small solar power plants using smart-off grid, and the implementation of various connected projects.

Russia-Central Asia relations -Focusing on the period after the establishment of the EAEU in 2015- (러시아·중앙아시아 관계 -2015년 EAEU 창설 이후를 중심으로-)

  • Sang Nam Park
    • Analyses & Alternatives
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    • v.7 no.3
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    • pp.85-114
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    • 2023
  • The purpose of this study is to analyze Russia-Central Asia relations since the launch of the EAEU in 2015 and forecast the future from a structural realism perspective. Bilateral relations have both elements of close cooperation and elements of conflict. Russia and Central Asia, which have the characteristics of an authoritarian alliance, also have a symbiotic relationship in which they have no choice but to cooperate with each other to maintain the regime. Based on this, Russia has made various efforts to reunify Central Asia. Central Asia also has no choice but to cooperate with Russia for its survival, but at the same time, it has expanded its scope of cooperation in the international community to avoid being subjugated to Russia again. However, as China's power expands, Russia's relative weakness, and wariness toward Russia increases after the Ukraine War, the gap in bilateral relations is widening. In particular, as China's influence grows, Russia's nervousness also increases. This is why Putin visits Central Asia and holds active summit talks even during the war in Ukraine. If competition between Russia and China surfaces, there is a high possibility that the international order in Central Asia will become unstable. However, it is still unlikely that the power of Russia and China will reverse in Central Asia. Above all, the security, historical, and cultural connections between Russia and Central Asia are areas that are difficult for China to catch up with. Therefore, a weakening of Russia's influence compared to the past is inevitable, but its superiority is expected to continue. If Russia breaks away from belligerence and transforms into an attractive cooperative partner, there is a possibility that bilateral relations will take an upward turn again. However, it seems unlikely that such changes and innovations will occur under the Putin regime. Therefore, the biggest obstacle to realizing Putin's goal of reunifying Central Asia is Putin himself.

Scaling Attack Method for Misalignment Error of Camera-LiDAR Calibration Model (카메라-라이다 융합 모델의 오류 유발을 위한 스케일링 공격 방법)

  • Yi-ji Im;Dae-seon Choi
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.33 no.6
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    • pp.1099-1110
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    • 2023
  • The recognition system of autonomous driving and robot navigation performs vision work such as object recognition, tracking, and lane detection after multi-sensor fusion to improve performance. Currently, research on a deep learning model based on the fusion of a camera and a lidar sensor is being actively conducted. However, deep learning models are vulnerable to adversarial attacks through modulation of input data. Attacks on the existing multi-sensor-based autonomous driving recognition system are focused on inducing obstacle detection by lowering the confidence score of the object recognition model.However, there is a limitation that an attack is possible only in the target model. In the case of attacks on the sensor fusion stage, errors in vision work after fusion can be cascaded, and this risk needs to be considered. In addition, an attack on LIDAR's point cloud data, which is difficult to judge visually, makes it difficult to determine whether it is an attack. In this study, image scaling-based camera-lidar We propose an attack method that reduces the accuracy of LCCNet, a fusion model (camera-LiDAR calibration model). The proposed method is to perform a scaling attack on the point of the input lidar. As a result of conducting an attack performance experiment by size with a scaling algorithm, an average of more than 77% of fusion errors were caused.

A Study on the Application of Classic Astrology to Predict Occupational Integrity (직업적성 예측을 위한 고전 점성학 활용방안)

  • Do-Yeon Kim;Ki-Seung Kim
    • Industry Promotion Research
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    • v.8 no.4
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    • pp.221-227
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    • 2023
  • This study is a study to analyze Nativity's occupational aptitude by examining the functions and structures of the planets that make up the Nativity birth chart of Classic Astrology. If the occupation that appears in the birth chart is viewed as an individual's natural occupation, it is analyzed through the strength and weakness of the sign and planets, and the aspect (relationship with the planet). In Classic Astrology's nativity birth chart, there are three major planets when judging occupations: Venus (♀). Mars (♂). It was thought to be determined by Mercury (☿). However, in order to meet the diversity of jobs required in today's highly developed knowledge and information society, there are some shortcomings, so Saturn (♄), Jupiter (♃), Sun (☉), Moon (☽) was added to apply the aptitude for the job. Thus, the native's ASC vocational aptitude could be applied more diversely and broadly based on the relationship between planets and their aspects. As a result, Venus (♀. Venus) means enjoying artistic work that people think is beautiful and making it a pleasure in life, while Mars (♂) means work that requires physical strength and strength, such as working days. Mercury (☿) means using knowledge and brains, and the Sun (☉) plays a role in giving authority to jobs and talents. The Moon (☽) helps the native gain people's trust in his or her profession and talents, Jupiter (♃) helps the native to revive his or her profession and talents through faith, sincerity, fairness, and generosity, and Saturn (♄) can appear as an obstacle that blocks career and talent due to greed, sadness, poverty, etc. As a result of the study, it was found that the native's occupations vary depending on the strengths and weaknesses of the planets and their aspect relationships.

A Validation Study of the Korean Version of the Workplace Intergenerational Climate Scale(K-WICS) (한국판 세대친화적 조직문화척도(K-WICS) 타당화 연구)

  • Seoyeong Jeong;Hee Woong Park;Young Woo Sohn
    • Korean Journal of Culture and Social Issue
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    • v.29 no.4
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    • pp.429-453
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    • 2023
  • Due to recent demographic changes, employees from diverse generations now work together in organizations. Thus, there is a need for research on intergenerational cooperation. However, the lack of valid and reliable measures to capture intergenerational climate in the workplace is an obstacle to research. Therefore, we translated the Workplace Intergenerational Climate Scale(WICS) into Korean and validated it with a sample of 1,052 Korean full-time employees. Firstly, we conducted an exploratory factor analysis by using sample 1(N = 460) and revealed a five-factor solution. Secondly, the confirmatory factor analysis(sample 2; N = 592) showed a good model fit of the correlated five-factor model. Thirdly, the scale's discriminant and convergent validity was supported by negative correlations with four types of existing ageism scales and by positive correlations with trust, organizational commitment, work engagement, psychological safety, intention to remain, job satisfaction, and communication satisfaction. Moreover, it further demonstrated significant incremental validity in predicting positive outcome variables even when controlling for pre-existing agism scales. Lastly, we confirmed strict measurement invariance of the scale between the age groups(below 40 versus above 40). The findings support the reliability and validity of the Korean version of WICS among Korean employees. The scale will be broadly applied to measure intergenerational climate of organizations and provide practical implications for HR management.

Implementation of AI-based Object Recognition Model for Improving Driving Safety of Electric Mobility Aids (객체 인식 모델과 지면 투영기법을 활용한 영상 내 다중 객체의 위치 보정 알고리즘 구현)

  • Dong-Seok Park;Sun-Gi Hong;Jun-Mo Park
    • Journal of the Institute of Convergence Signal Processing
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    • v.24 no.2
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    • pp.119-125
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    • 2023
  • In this study, we photograph driving obstacle objects such as crosswalks, side spheres, manholes, braille blocks, partial ramps, temporary safety barriers, stairs, and inclined curb that hinder or cause inconvenience to the movement of the vulnerable using electric mobility aids. We develop an optimal AI model that classifies photographed objects and automatically recognizes them, and implement an algorithm that can efficiently determine obstacles in front of electric mobility aids. In order to enable object detection to be AI learning with high probability, the labeling form is labeled as a polygon form when building a dataset. It was developed using a Mask R-CNN model in Detectron2 framework that can detect objects labeled in the form of polygons. Image acquisition was conducted by dividing it into two groups: the general public and the transportation weak, and image information obtained in two areas of the test bed was secured. As for the parameter setting of the Mask R-CNN learning result, it was confirmed that the model learned with IMAGES_PER_BATCH: 2, BASE_LEARNING_RATE 0.001, MAX_ITERATION: 10,000 showed the highest performance at 68.532, so that the user can quickly and accurately recognize driving risks and obstacles.

Validation and Development of the Driving Stress Scale (운전 스트레스 척도(Driving Stress Scale: DSS)의 개발과 타당화 연구)

  • Soon yeol Lee;Soon chul Lee
    • Korean Journal of Culture and Social Issue
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    • v.14 no.3
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    • pp.21-40
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    • 2008
  • This study was intended to validate and develop the driving stress scale. In a preliminary investigation, literature studies on the stress and open questionnaire were administered and examined in four regions in Korea. As a result, 121 items driving stress questionnaire were developed. In the study, this driving stress questionnaire was examined to 450 drivers located seven regions in Korea. The factors analysis revealed 5 meaningful factors[(Progress Obstacle: PO), (Traffic Circumstance: TC), (Accident & Regulation: AR), (Regulation Observance: RO), (Time Pressure: TP)] with 38 items. When internal consistency for each 5 factor was calculated, all sub-scale revealed a satisfactory level of Cronbach's α. Also, correlations with Driving Behaviour Inventory-General Driver Stress(DBI-GEN) and risk driving behaviors(speed driving, drunken driving, offence accident, defence accident) supported consistently validity of the Driving Stress Scale(DSS). Finally the result were discussed and implications are suggested for future studies.

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The Influences of Speed desire frustration on Driving Stress (운전자의 속도 욕구좌절이 운전 스트레스에 미치는 영향)

  • Soon yeol Lee ;Soon chul Lee
    • Korean Journal of Culture and Social Issue
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    • v.15 no.2
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    • pp.319-338
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    • 2009
  • This study was intended to recognize whether speed desire frustration influences in driving stress. Stress desire frustration is the difference between prefer speed and normal speed. As a result, driver's the prefer speed is higher than the normal speed on 4 road condition(high-way, urban-way, residential-way, rural-way). Also, driver's speed desire frustration caused statistical effect in driving stress on 4 road condition. speed desire frustration effect Driving Stress Scale(DSS) 5 sub-scale factors(progress obstacle, traffic circumstance, accident & regulation, regulation obedience, time pressure). This is that driver who experience much speed desire frustration creates high driving stress. Speed desire frustration analyzed high driver and low driver's Driving Stress Scale(DSS) score and overspeed regulation and traffic accident experience difference. As analysis result, speed desire frustration high driver driving stress high appear. However, difference of overspeed regulation experience or traffic accident experience by speed desire frustration did not appear.

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Comparative study of laminar and turbulent models for three-dimensional simulation of dam-break flow interacting with multiarray block obstacles (다층 블록 장애물과 상호작용하는 3차원 댐붕괴흐름 모의를 위한 층류 및 난류 모델 비교 연구)

  • Chrysanti, Asrini;Song, Yangheon;Son, Sangyoung
    • Journal of Korea Water Resources Association
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    • v.56 no.spc1
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    • pp.1059-1069
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    • 2023
  • Dam-break flow occurs when an elevated dam suddenly collapses, resulting in the catastrophic release of rapid and uncontrolled impounded water. This study compares laminar and turbulent closure models for simulating three-dimensional dam-break flows using OpenFOAM. The Reynolds-Averaged Navier-Stokes (RANS) model, specifically the k-ε model, is employed to capture turbulent dissipation. Two scenarios are evaluated based on a laboratory experiment and a modified multi-layered block obstacle scenario. Both models effectively represent dam-break flows, with the turbulent closure model reducing oscillations. However, excessive dissipation in turbulent models can underestimate water surface profiles. Improving numerical schemes and grid resolution enhances flow recreation, particularly near structures and during turbulence. Model stability is more significantly influenced by numerical schemes and grid refinement than the use of turbulence closure. The k-ε model's reliance on time-averaging processes poses challenges in representing dam-break profiles with pronounced discontinuities and unsteadiness. While simulating turbulence models requires extensive computational efforts, the performance improvement compared to laminar models is marginal. To achieve better representation, more advanced turbulence models like Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) are recommended, necessitating small spatial and time scales. This research provides insights into the applicability of different modeling approaches for simulating dam-break flows, emphasizing the importance of accurate representation near structures and during turbulence.

Proposal for Research Model of High-Function Patrol Robot using Integrated Sensor System (통합 센서 시스템을 이용한 고기능 순찰 로봇의 연구모델 제안)

  • Byeong-Cheon Yoo;Seung-Jung Shin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.3
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    • pp.77-85
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    • 2024
  • In this dissertation, a we designed and implemented a patrol robot that integrates a thermal imaging camera, speed dome camera, PTZ camera, radar, lidar sensor, and smartphone. This robot has the ability to monitor and respond efficiently even in complex environments, and is especially designed to demonstrate high performance even at night or in low visibility conditions. An orbital movement system was selected for the robot's mobility, and a smartphone-based control system was developed for real-time data processing and decision-making. The combination of various sensors allows the robot to comprehensively perceive the environment and quickly detect hazards. Thermal imaging cameras are used for night surveillance, speed domes and PTZ cameras are used for wide-area monitoring, and radar and LIDAR are used for obstacle detection and avoidance. The smartphone-based control system provides a user-friendly interface. The proposed robot system can be used in various fields such as security, surveillance, and disaster response. Future research should include improving the robot's autonomous patrol algorithm, developing a multi-robot collaboration system, and long-term testing in a real environment. This study is expected to contribute to the development of the field of intelligent surveillance robots.