• Title/Summary/Keyword: Focus distance

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A Study on the Integrated System Implementation of Close Range Digital Photogrammetry Procedures (근거리 수치사진측량 과정의 단일 통합환경 구축에 관한 연구)

  • Yeu, Bock-Mo;Lee, Suk-Kun;Choi, Song-Wook;Kim, Eui-Myoung
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.1 s.13
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    • pp.53-63
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    • 1999
  • For the close range digital photogrammetry, multi-step procedures should be embodied in an integrated system. However, it is hard to construct an Integrated system through conventional procedural processing. Using Object Oriented Programming(OOP), photogrammetric processings can be classified with corresponding subjects and it is easy to construct an integrated system lot digital photogrammetry as well as to add the newly developed classes. In this study, the equation of 3-dimensional mathematic model is developed to make an immediate calibration of the CCD camera, the focus distance of which varies according to the distance of the object. Classes for the input and output of images are also generated to carry out the close range digital photogrammetric procedures by OOP. Image matching, coordinate transformation, dirct linear transformation and bundle adjustment are performed by producing classes corresponding to each part of data processing. The bundle adjustment, which adds the principle coordinate and focal length term to the non-photogrammetric CCD camera, is found to increase usability of the CCD camera and the accuracy of object positioning. In conclusion, classes and their hierarchies in the digital photogrammetry are designed to manage multi-step procedures using OOP and close range digital photogrammetric process is implemented using CCD camera in an integrated System.

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Analysis of PLAN Modernization Trend and Prospects for Balance of U.S-China Naval power in the East Asia (중국해군(PLAN)의 현대화 추세와 동아시아 지역의 미·중 해군력 균형 전망)

  • Kwon, Jeong Wook
    • Strategy21
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    • s.43
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    • pp.5-28
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    • 2018
  • The tensions between the U.S and China, which form the two pillars of the G2 era, seem to have persisted even after the Trump administration inaugurated. The strong confrontation between the two in recent foreign security issues may drive to develop an inadvertent military conflict, and it is high likely to occur in the maritime are. The purpose of this study is not only to analyze the balance of modernized naval forces in the PLAN through naval strategy changes and weapons system modernization trend, but also to predict the impact of the geographical proximity difference on the balance of naval forces in the disputed areas. It examined the impact of distance and geography on naval power by assessing the modernization pattern of the PLAN and capabilities in the context of two scenarios at different distances from China by 2020: one centered on Taiwan and the other on the Spratly Islands. The PLAN's strategy had impact on operational concept and forces construction. First, from the viewpoint of operation operational concept, it can be seen that the passive defense is changing into active defense. Second, in terms of power construction, it can threaten the surface and submarines of U.S power from a distance. And they generated follow three features; The ocean is not the focus of Chinese submarines, Horizontal and vertical expansion of Chinese naval vessels, The improvement of the suppression ability as the Chinese naval modernization ratio increases. The strength of the PLAN is dominant over the U.S in terms of reserves, and it can complement the qualitative deterioration by utilizing nearby bases in the vicinity of the mainland, such as the Taiwan Strait. However, due to the shortage of aircraft carriers, there is a possibility that it will take some time to secure the advantage of air and ocean in the amphibious operation. Therefore, as the dispute is prolonged, China may fail to achieve its original goal. In addition, the lack of cutting edge Commanding Ships may bring to weaken the C2 capabilities. At results, it is expected that PLAN will not be able to have a superiority in the short term due to lagging behind U.S advanced technology. Nevertheless, PLAN has strengthened its naval power through modernization sufficiently and it is highly likely to use force. Especially, it is more likely in the region where the naval power operation like the Taiwan Strait is possible with the almost equality to that of the United States. China will continue to use its naval forces to achieve a rapid and decisive victory over U.S in the close area from the land.

Object Detection Method on Vision Robot using Sensor Fusion (센서 융합을 이용한 이동 로봇의 물체 검출 방법)

  • Kim, Sang-Hoon
    • The KIPS Transactions:PartB
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    • v.14B no.4
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    • pp.249-254
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    • 2007
  • A mobile robot with various types of sensors and wireless camera is introduced. We show this mobile robot can detect objects well by combining the results of active sensors and image processing algorithm. First, to detect objects, active sensors such as infrared rays sensors and supersonic waves sensors are employed together and calculates the distance in real time between the object and the robot using sensor's output. The difference between the measured value and calculated value is less than 5%. We focus on how to detect a object region well using image processing algorithm because it gives robots the ability of working for human. This paper suggests effective visual detecting system for moving objects with specified color and motion information. The proposed method includes the object extraction and definition process which uses color transformation and AWUPC computation to decide the existence of moving object. Shape information and signature algorithm are used to segment the objects from background regardless of shape changes. We add weighing values to each results from sensors and the camera. Final results are combined to only one value which represents the probability of an object in the limited distance. Sensor fusion technique improves the detection rate at least 7% higher than the technique using individual sensor.

An Experimental Study on the Fire Monitoring System for Tunnel Using SMA and Fiber Optic Cable (형상기억합금과 광케이블을 이용한 터널의 화재감지 시스템 개발에 관한 실험적 연구)

  • Hwang, Ji-Hyun;Park, Ki-Tae;Lee, Kyu-Wan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.5
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    • pp.128-134
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    • 2014
  • Recently, design and construction of street tunnels tend to focus on cost reduction and preservation of nature. Accordingly, research is actively being carried out to quickly detect fires when they occur in tunnels, which have partially closed structures. Among such research, fire detection methods using optical fiber sensors have a wide bandwidth and fast transmission speed, while using light as a medium. Therefore, it does not receive electrical interference and there is almost no loss of information during transmission, while also having little noise as well. In relation to this, a fire monitoring system that can accurately detect the location of fires in real time using shape memory alloy and optical cables was developed in this study. In order to verify the developed method, light loss measurement test was conducted according to indoor temperature changes, while also conducting fire simulation tests by installing test beds in common underground zones with different external environments of temperature and distance. Upon carrying out experiments, the fire monitoring system developed in this study was found to be able to detect fires in long distance sections in real time.

The Estimated Evacuation Time for the Emergency Planning Zone of the Kori Nuclear Site, with a Focus on the Precautionary Action Zone

  • Lee, Janghee;Jeong, Jae Jun;Shin, Wonki;Song, Eunyoung;Cho, Cheolwoo
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.196-205
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    • 2016
  • Background: The emergency planning zone (EPZ) of the city of Busan is divided into the precautionary actions zone (PAZ) and the urgent protective action planning zone; which have a 5-km radius and a 20-km to 21-km radius from the nuclear power plant site, respectively. In this study, we assumed that a severe accident occurred at Shin-Kori nuclear unit 3 and evaluated the dispersion speed of radiological material at each distance at various wind speeds, and estimated the effective dose equivalent and the evacuation time of PAZ residents with the goal of supporting off-site emergency action planning for the nuclear site. Materials and Methods: The total effective dose equivalent, which shows the effect of released radioactive materials on the residents, was evaluated using the RASCAL 4.2 program. In addition, a survey of 1,036 residents was performed using a standardized questionnaire, and the resident evacuation time according to road and distance was analyzed using the VISSIM 6.0 program. Results and Discussion: According to the results obtained using the VISSIM and RASCAL programs, it would take approximately 80 to 252.2 minutes for permanent residents to move out of the PAZ boundary, 40 to 197.2 minutes for students, 60 to 232.2 minutes for the infirm, such as elderly people and those in a nursing home or hospital, and 30 to 182.2 minutes for those temporarily within the area. Consequently, in the event of any delay in the evacuation, it is estimated that the residents would be exposed to up to $10mSv{\cdot}h^{-1}$ of radiation at the Exclusion Area Boundaries (EAB) boundary and $4-6mSv{\cdot}h^{-1}$ at the PAZ boundary. Conclusion: It was shown that the evacuation time for the residents is adequate in light of the time lapse from the initial moment of a severe accident to the radiation release. However, in order to minimize the evacuation time, it is necessary to maintain a system of close collaboration to avoid traffic congestion and spontaneous evacuation attempts.

A Study on Evaluation of Slope Stability and Range of Rockfall Hazard of Daljeon-ri Columnar Joint in Pohang, Korea (천연기념물 제415호 포항 달전리 주상절리의 사면안정성 평가 및 낙석 위험 범위 설정)

  • Kim, Jae Hwan;Kang, Mu Hwan;Kong, Dal-Yong;Jwa, Yong-Joo
    • Journal of Conservation Science
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    • v.37 no.5
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    • pp.505-515
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    • 2021
  • In this study, we evaluated the slope stability of the Pohang Daljeon-ri columnar joint (Natural Monuments # 415) and calculated the maximum energy, jumping height and moving distance of rockfalls using a simulation. Based on the results, we established the range of rockfall risk. The slopes of the Pohang Daljeon-ri columnar joint have dip directions of 93.79°, 131.99°, 165.54° and 259.84° from left (SW) to right (NE). Furthermore, they have a fan-like shape. The Pohang Daljeon-ri columnar joints are divided into four sections depending on the dip direction. The measurement results of the discontinuous face show that zone 1 is 125, zone 2 is 261, zone 3 is 262, zone 4 is 43. The results of slope stability analyses for each section using a stereographic projection method correspond to the range of planar and toppling failure. Although it is difficult to diagnose the type of failure, risk evaluation of currently falling rocks requires further focus. The maximum movement distance of a rockfall in the simulation was approximately 66 m and the rockfall risk range was the entire area under slope. In addition, it is difficult to forecast where a rock will fall as it rolls in various directions due to topographic factors. Thus, the installation of measures to prevent falling is suggested to secure the stability based on the results of the rockfall simulations and its probabilistic analysis.

A Study on the Establishment of Allowable Criteria for Sailing Ships at Offshore Wind Farms (해상풍력발전단지해역 선박 통항 허용기준 설정에 관한 연구)

  • Ohn, Sung-Wook;Lee, Chang-Hyun;Kim, Cheol-Seong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.841-847
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    • 2018
  • Since global energy consumption and demand for energy have dramatically risen, a focus on environmental problems and sustainability has become more important. Clean and renewable energy sources such as offshore wind power generation have received attention among new renewable energy options as alternative energy resources. Due to maintenance and operational perspectives, offshore wind farms have been planned for installation in many coastal waters. However, development of offshore wind farms faces interference from existing maritime traffic along the planned areas. In order to safely and effectively govern marine traffic in the vicinity of wind farms and inner areas, standard criteria are suggested to allow vessels to sail the internal waters of offshore wind farm areas. Therefore, the purpose of this study is to establish allowable criteria for sailing vessels and safety zones for offshore wind farms by investigating the local regulations of various offshore wind farm cases overseas. The commended inner safety zone of wind farms is proposed to be a distance of 150 % of the rotation diameter of the wind turbine rotor and a distance of 200 m from the outer wind turbine for the outer safety zone. Besides this, the allowable criteria for sailing vessels within a wind farm is proposed to have an air draft of 14.47 m south-west wind farm sea areas for a minimum margin to avoid hull contact through evaluation of the tide and height of a wind turbine. further studies will be needed to establish vessel sailing criteria among adjacent offshore wind farms as well as vessel sailing criteria within a single offshore wind farm.

Design and Implementation of Visitor Access Control System using Deep learning Face Recognition (딥러닝 얼굴인식 기술을 활용한 방문자 출입관리 시스템 설계와 구현)

  • Heo, Seok-Yeol;Kim, Kang Min;Lee, Wan-Jik
    • Journal of Digital Convergence
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    • v.19 no.2
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    • pp.245-251
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    • 2021
  • As the trend of steadily increasing the number of single or double household, there is a growing demand to see who is the outsider visiting the home during the free time. Various models of face recognition technology have been proposed through many studies, and Harr Cascade of OpenCV and Hog of Dlib are representative open source models. Among the two modes, Dlib's Hog has strengths in front of the indoor and at a limited distance, which is the focus of this study. In this paper, a face recognition visitor access system based on Dlib was designed and implemented. The whole system consists of a front module, a server module, and a mobile module, and in detail, it includes face registration, face recognition, real-time visitor verification and remote control, and video storage functions. The Precision, Specificity, and Accuracy according to the change of the distance threshold value were calculated using the error matrix with the photos published on the Internet, and compared with the results of previous studies. As a result of the experiment, it was confirmed that the implemented system was operating normally, and the result was confirmed to be similar to that reported by Dlib.

A Study for Improving the Golf Performance of Senior Male Golfers : a focus on Dynamic Warm-up Exercise (남자 노인의 골프 수행력 향상을 위한 연구 : 동적 준비운동을 중심으로)

  • Kwak, Kyu-Hoon;Jeong, Tchae-Won
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.7
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    • pp.69-77
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    • 2020
  • Korea's golf fever is as good as the United States, Europe and Japan, which are called golf powers. The senior golf population over 55 years old has exceeded 2.5 million, and they are more interested in improving golf performance than participating in golf. So, this study aims to emphasize the importance of dynamic preparation exercise by identifying the effects of dynamic preparation exercise on golf physical strength and golf batting in order to suggest a way to help the elderly men's golf performance. The experimental group(n=13) and the control group(n=14) were divided into two groups and repeated measurements were conducted by two-way ANOVA with pre- and post-design. As a result of the analysis, the flexibility factor showed a positive effect on golf physical strength, and in golf batting, head speed, distance, and attack angle showed interaction effect, which led to the conclusion that dynamic preparation exercise helped the golf performance of the elderly male. Therefore, the continuous dynamic preparation exercise led to positive transition to head speed and attack angle due to the increase in the flexibility of the body, which led to the improvement of distance and the increase in performance level.

A Research of Factors Affecting LiDAR's Detection on Road Signs: Focus on Shape and Height of Road Sign (도로표지에 대한 LiDAR 검지영향요인 연구: 도로표지의 모양과 높이를 중심으로)

  • Kim, Ji yoon;Park, Bum jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.4
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    • pp.190-211
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    • 2022
  • This study investigated the effect of the shape and height of road signs on detection performance when detecting road signs with LiDAR, which is recognized as an essential sensor for autonomous vehicles. For the study, four types of road signs with the same area and material and different shapes were produced, and a road driving test was performed by installing a 32Ch rotating LiDAR on the upper part of the vehicle. As a result of comparing the shape of the point cloud and the NPC according to the shape of the road sign, It is expected that a distance of less than 40m is required to recognize the overall shape of a road sign using 32Ch LiDAR, and shapes such as triangles and rectangles are more advantageous than squares in securing the maximum point cloud from a long distance. As a result of the study according to the height of the road sign, At short distances (within 20m), if the height of the sign is raised to more than 2m, it deviates from the vertical viewing angle of the LiDAR and cannot express the complete point cloud shape. However, it showed a negligible effect compared to the near-field height change. These research results are expected to be utilized in the development of road facilities dedicated to LiDAR for the commercialization of autonomous cooperative driving technology.