• Geophysics and Geophysical Exploration
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• v.15 no.2
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• pp.85-91
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• 2012

Multiple Lapse Time Window (MLTW) analysis for obtaining intrinsic attenuation value require numerous data without directional bias to compensate focal mechanism. The first window of MLTW, therefore, shows large deviation in fitting smoothed theoretical curve. The information on the focal mechanism may reduce burdens of number and distribution. This study combined algorithm of computing focal mechanism to DSMC method by Yoshimoto (2000). However, the MLTW method based on the numerous data was not applicable to this study, because of the limited data to the almost same fault plane solution. This study showed that the available data was too insufficient to construct smoothed theoretical curve, although the deviation of the first window was improved. Instead of conventional solution by more data, the study seems to be needed for new constraints to obtain smoothed curve.

• Tunnel and Underground Space
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• v.29 no.2
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• pp.89-107
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• 2019

Rock joints have an extremely important role in analyzing the mechanical stability and hydraulic characteristics of rock mass structures. Most rock joint parameters are generally indicated as a distribution by statistical techniques. In this research, calculation technique of Joint Center Volume (JCV) is analyzed, which is required for estimating the size distribution having the largest uncertainty among the joint parameters, then a new technique is proposed which is applicable regardless of the shape of survey window. The existing theoretical JCV calculation technique can be applied only to the plane window, and the complete enumeration techniques show the limitations in joint trace type and analysis time. This research aims to overcome the limitations in survey window shape and joint trace type through calculating JCV by using Monte Carlo simulation. The applicability of proposed technique is validated through the estimation results at non-planar survey windows such as curved surface and tunnel surface.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.323-330
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• 2003

GIS-based applications for route guidance are increasingly developed recently, but most of them are for self$.$driven cars. Although some of them are intended for public transportation, they show limitations in dealing with time constraints problems taken place in transfer areas. Developing a public transportation guidance system requires the fallowing aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggests the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints. The method for constructing the data structure in the GIS was also suggested.

• Journal of the Korea Society for Simulation
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• v.20 no.4
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• pp.127-138
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• 2011

Certified Missile Round Concepts that is one-shot device use the periodic inspection policy to improve the continuously deteriorated reliability. In this paper, we suggest dormant reliability prediction model by simulation with real operational environment. The suggested prediction model is based on optimal inspection period decision model and additionally considers various constraints; moving, inspection or repair service time. The simulation results show the constraints affect dormant reliability and missile availability. Lastly, we suggest building up a depot to resolve the above problems by the suggested simulation model.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.10
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• pp.493-501
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• 2007

The imprecise real-time system provides flexibility in scheduling time-critical tasks. Most scheduling problems of satisfying both 0/1 constraint and timing constraints, while the total error is minimized, are NP-complete when the optional tasks have arbitrary processing times. Liu suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on uniprocessors for minimizing the total error. Song et at suggested a reasonable strategy of scheduling tasks with the 0/1 constraint on multiprocessors for minimizing the total error. But, these algorithms are all off-line algorithms. In the online scheduling, the NORA algorithm can find a schedule with the minimum total error for the imprecise online task system. In NORA algorithm, EDF strategy is adopted in the optional scheduling. On the other hand, for the task system with 0/1 constraint, EDF_Scheduling may not be optimal in the sense that the total error is minimized. Furthermore, when the optional tasks are scheduled in the ascending order of their required processing times, NORA algorithm which EDF strategy is adopted may not produce minimum total error. Therefore, in this paper, an online algorithm is proposed to minimize total error for the imprecise task system with 0/1 constraint. Then, to compare the performance between the proposed algorithm and NORA algorithm, a series of experiments are performed. As a conseqence of the performance comparison between two algorithms, it has been concluded that the proposed algorithm can produce similar total error to NORA algorithm when the optional tasks are scheduled in the random order of their required processing times but, the proposed algorithm can produce less total error than NORA algorithm especially when the optional tasks are scheduled in the ascending order of their required processing times.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.300-302
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• 2013

자연재해의 예방에 대한 인식이 화두가 되면서 최근 재해 경보 시스템을 다루는 새로운 연구들이 활발히 진행되고 있다. 제안하는 알고리듬은 영상을 통해 얻은 정보를 이용하여 산사태를 초기에 검출하는 방법이다. 기존의 검출 방법은 사람이 직접 모니터링을 해야 하기 때문에 많은 인력과 시간을 필요로 하고 접근성이나 비용문제 등의 각종 제약이 따른다. 따라서 효율적인 산사태 감지를 위해 산사태 발생 가능 지역에 비디오 기반의 감지 시스템을 통해서 자동으로 검출하는 시스템이 필요하다. 감지 시스템에서는 신뢰성 있는 재난영역의 검출이 매우 중요하다고 볼 수 있다. 본 연구는 산사태를 검출하기 위하여 먼저 블록단위의 영역 움직임 검출을 하여, 움직임 맵을 만들고 일정한 시간 간격으로 반복적으로 변하는 영역의 움직임 맵을 기록한다. 또한 움직임 방향뿐만 아니라 발생 순서를 기록하여 더욱더 정확한 움직임을 판단할 수 있다. 제안된 알고리듬은 비디오영상 실험을 통해 탐지영역의 산사태 검출이 잘 이루어짐을 확인하였다.

• The Magazine for Energy Service Companies
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• s.54
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• pp.64-69
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• 2008

야간의 잉여전력으로 열을 저장해두었다 주간에 이용하는 축열공조에는 50여년에 걸친 긴 역사가 있었다. 이 방식이 가지는 효용에 일찍부터 눈뜬 선각자들의 노력에도 불구하고 당초 보급은 늦어져 그다지 진전이 없었다고 한다. 이러한 정세가 일변한 것은 전력공급에 병목현상이 생겨 부하 평준화가 안정공급에 있어 필요불가결의 과제가 되었기 때문이다. 특히 공조는 피크성이 강한 수요이므로 공조용 전력을 야간으로 옮기는 작업의 이점이 큰 것은 당연하다. 비 수요시간대의 요금이 큰 폭으로 떨어짐으로써 수요자측에서 보아도 야간의 전력을 어떻게 활용할까하는 것은 매력적인 연구테마였다. 이리하여 축열공조가 관심을 불러 보급이 기도에 놓인 지 2O년 가까이 되었다. 처음에는 물을 사용한 축열이 대부분이었으나, 축열조 용량의 제약으로 얼음을 만들어 저장하는 빙축열방식이 도입되어 현재의 표준적인 축열방식이되었다. 그러나 빙축열에도 비용상의 문제가 있어 전면적인 보급에 이르기까지는 아직 연구의 여지가 더 남아있는 듯하다. 한편, 교토의정서의 발효 등에 의해 지구환경에 대한 관심이 높아지게 되었다. 이 같은 배경 속에 건물및 건축설비의 에너지절약 기술의 중요성이 대두되고, 특히 창 주변의 공조방식, 조광제어, 축열 공조시스템 등, 건물부하의 직접적인 저감과 전력부하 평준화에 의한 환경부하저감 및 운영비용의 저감을 목적으로 한 건물일체형 설비시스템을 적극적으로 도입하기에 이르렀다. 환경을 배려한 건축구조.설비시스템의 채택 사례가 증가하며 건축물 종합환경성능 평가시스템과 성능검증 등 건물설비의 평가.검증 수법도 연구되어 건물에 적합한 운용면에서의 사고가 중요함이 인식되었다. 이와 같이 건축구조와 설비시스템의 양면에서 에너지절약성 및 환경성, 쾌적성, 편리성의 추구가 적극적으로 도입되는 가운데, 슬래브축열시스템은 건축구조와 공조설비가 균형있게 융합됨으로써 초기비용의 삭감과 부하 평준화에 의한 경제성 향상, 복사에의한 실내환경의 향상 등의 효과를 기대할 수있는 시스템으로 추목받고 있다.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.1 s.9
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• pp.57-70
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• 1997

Conventional procedures to determine vertical deflections and astronomical coordinates require the stellar observations which be under restraints of clear night-time weather conditions, surrounding environment, long observation time and the use of instruments, etc. Therefore the more effective observation method subjugatting these problems has requested. The objective of this study is to propose method to compute vertical deflections, astronomical coordinates(latitude and longitude), and astronomical azimuth by mixing GPS observation results and orthometric heights. For this study, programmed the program which able to obtain the change in geoid undulation by using the GPS- determined geodetic height difference and the orthometric height difference, and GPS satellite surveying was performed at both ten points of astronomical points and four triangulation points around each astronomical station in South Korea. The Astronomical results determined from GPS observations compared to those determined from both conventional astronomical measurements and the recent earth gravitational Model(EGM96).

• Journal of Internet of Things and Convergence
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• v.10 no.5
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• pp.27-37
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• 2024

In the context of multi-vehicle and multi-task logistics distribution within a park, traditional algorithms are often hindered by high computational complexity and slow convergence rates. Particle Swarm Optimization (PSO) has gained popularity in path planning for autonomous delivery vehicles due to its straightforward algorithmic principles, broad applicability, and comprehensive search capabilities. However, the conventional PSO is susceptible to premature convergence, leading to local optima. To address this, this study incorporates the Tent map into the PSO to enhance the algorithm's global search ability and prevent premature convergence. Benchmark function tests demonstrate that the improved Particle Swarm Optimization algorithm (TPSO), as proposed in this study, exhibits faster convergence and greater accuracy.In the instance verification section, X Park was selected as an example to construct a multi-vehicle and multi-task model for the logistics distribution within the park. The TPSO algorithm proposed in this paper was used to solve the model, and finally, the superiority of the TPSO algorithm was verified through comparative simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.524-527
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• 2008

Recently, digital and the Internet are widespread out of the world, and multimedia processing technology and the development of information and communication technology in education using the Internet as the demand is rapidly increasing. Also, we tan easily use informations with less restrictions of time and space. however, several kinds of audio, media to integrate multimedia data, such as the proliferation of demands for representation. Therefore, in 1998, W3C presented an international standard, SMIL in order to solve multimedia object representation and synchronization problems. By using SMIL, various multimedia elements can be integrated as a multimedia document with proper view in a spate and time. Using this SMIL document, we can create new internet radio broadcasting service that delivers not noly audio data but also various text, image and video. In this paper, with the system, teachers can easily create multimedia courseware and living broadcast their torture on network, students can receive audio-video information of the teacher, screen displays of the teachers computer. Moreover students can communicate with teacher simultaneously by text editor windows. Students can also order courseware after class.