• Title/Summary/Keyword: area-time complexity

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A Study on the Data Analysis of Fire Simulation in Underground Utility Tunnel for Digital Twin Application (디지털트윈 적용을 위한 지하공동구 화재 시뮬레이션의 데이터 분석 연구)

  • Jae-Ho Lee;Se-Hong Min
    • Journal of the Society of Disaster Information
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    • v.20 no.1
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    • pp.82-92
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    • 2024
  • Purpose: The purpose of this study is to find a solution to the massive data construction that occurs when fire simulation data is linked to augmented reality and the resulting data overload problem. Method: An experiment was conducted to set the interval between appropriate input data to improve the reliability and computational complexity of Linear Interpolation, a data estimation technology. In addition, a validity verification was conducted to confirm whether Linear Interpolation well reflected the dynamic changes of fire. Result: As a result of application to the underground common area, which is the study target building, it showed high satisfaction in improving the reliability of Interpolation and the operation processing speed of simulation when data was input at intervals of 10 m. In addition, it was verified through evaluation using MAE and R-Squared that the estimation method of fire simulation data using the Interpolation technique had high explanatory power and reliability. Conclusion: This study solved the data overload problem caused by applying digital twin technology to fire simulation through Interpolation techniques, and confirmed that fire information prediction and visualization were of great help in real-time fire prevention.

Analysis on Inundation Impacts of Sea Level Rise Using System Dynamics-GIS Model (System Dynamics-GIS 모델을 이용한 해수면 상승 침수 영향 분석)

  • KIM, Ji-Sook;KIM, Ho-Yong;LEE, Sung-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.18 no.2
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    • pp.92-104
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    • 2015
  • In order to analyze the impacts of climate change, a time and space integrated model was developed in this study using system dynamics and GIS. The model built was used to carry out a simulation on the inundation impact on A-gu of Busan Metropolitan city resulting from the sea level rise scenario of IPCC and storm surge, which is the worst case. Through this, the flooded area and population until 2100 were predicted. Also, the result and significance of each alternative was reviewed improving the model by establishing alternative scenarios of protection, accommodation and retreat as plans of reaction to sea level rise. The combination of system dynamics and GIS has advantages of how the diverse variables change until the target year can be traced and, accordingly, not only the results but also the processes of spatial change can be examined by calculating the value of change process at each time step. The synergy of this model presumed to be a foothold for solving problems which are becoming difficult to predict due to increase in uncertainty and complexity such as the support for decision making for urban resilience to natural disasters.

A Self Organization of Wavelet Network Structure by Generation and Extinction of Hidden Nodes (은닉노드의 생성 ${\cdot}$ 소멸에 의한 웨이블릿 신경망 구조의 자기 조직화)

  • Lim, Sung-Kil;Lee, Hyon-Soo
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.12
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    • pp.78-89
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    • 1999
  • Previous wavelet network structures are determined by considering the relationship between wavelet windows distribution of training patterns that are transformed into time-frequency space. Because it is separated two algorithms that determines wavelet network structure and that modifies parameters of network, learning process that minimizes output error of network is executed after the network structure is determined. But this method has some weakness that training patterns must be transformed into time-frequency space by additional preprocessing and the network structure should be fixed during learning process. In this paper, we propose a new constructing method for wavelet network structure by using differences between the output and the desired response without preprocessing. Because the algorithm perform network construction and error minimizing process simultaneously, it can determine the number of hidden nodes adaptively as with the complexity of problems. In addition, the network structure is optimized by inserting new hidden nodes in the area that has maximum error and extracting hidden nodes that has no effect to the output of network. This algorithm has no constraint condition that all training patterns must be known, because it removes preprocessing procedure for training patterns and it can be applied effectively to systems that has time varying outputs.

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Design of a Low-Power CMOS Fractional-N Frequency Synthesizer for 2.4GHz ISM Band Applications (2.4GHz ISM 대역 응용을 위한 저전력 CMOS Fractional-N 주파수합성기 설계)

  • Oh, Kun-Chang;Kim, Kyung-Hwan;Park, Jong-Tae;Yu, Chong-Gun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.6
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    • pp.60-67
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    • 2008
  • A low-power 2.4GHz fractional-N frequency synthesizer has been designed for 2.4GHz ISM band applications such as Bluetooth, Zigbee, and WLAN. To achieve low-power characteristic, the design has been focused on the power optimization of power-hungry blocks such as VCO, prescaler, and ${\Sigma}-{\Delta}$ modulator. An NP-core type VCO is adopted to optimize both phase noise and power consumption. Dynamic D-F/Fs with no static DC current are employed in designing the low-power prescaler circuit. The ${\Sigma}-{\Delta}$ modulator is designed using a modulus mapping circuit for reducing hardware complexity and power consumption. The designed frequency synthesizer which was fabricated using a $0.18{\mu}m$ CMOS process consumes 7.9mA from a single 1.8V supply voltage. The experimental results show that a phase noise of -118dBc/Hz at 1MHz offset, the reference spur of -70dBc at 25MHz offset, and the channel switching time of $15{\mu}s$ over 25MHz transition have been achieved. The designed chip occupies an area of $1.16mm^2$ including pads where the core area is only $0.64mm^2$.

A Novel Video Copy Detection Method based on Statistical Analysis (통계적 분석 기반 불법 복제 비디오 영상 감식 방법)

  • Cho, Hye-Jeong;Kim, Ji-Eun;Sohn, Chae-Bong;Chung, Kwang-Sue;Oh, Seoung-Jun
    • Journal of Broadcast Engineering
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    • v.14 no.6
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    • pp.661-675
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    • 2009
  • The carelessly and illegally copied contents are raising serious social problem as internet and multimedia technologies are advancing. Therefore, development of video copy detection system must be settled without delay. In this paper, we propose the hierarchical video copy detection method that estimates similarity using statistical characteristics between original video and manipulated(transformed) copy video. We rank according to luminance value of video to be robust to spacial transformation, and choose similar videos categorized as candidate segments in huge amount of database to reduce processing time and complexity. The copy videos generally insert black area in the edge of the image, so we remove rig black area and decide copy or not by using statistical characteristics of original video and copied video with center part of frame that contains important information of video. Experiment results show that the proposed method has similar keyframe accuracy to reference method, but we use less memory to save feature information than reference's, because the number of keyframes is less 61% than that of reference's. Also, the proposed method detects if the video is copied or not efficiently despite expansive spatial transformations such as blurring, contrast change, zoom in, zoom out, aspect ratio change, and caption insertion.

현대 서양복식에 나타난 이국취향 (Exoticism)에 관한 연구 -1980년대 중반~1991년의 서양복식을 중심으로- (The Study of Exoticism in Western Costume)

  • 송명진;양숙희
    • Journal of the Korean Society of Costume
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    • v.18
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    • pp.291-306
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    • 1992
  • From the mid-1980s '91s, remarkable Ethnicism and Primitivism in the Europe fashion trend could be represented as an exotic taste longing for secenery and emotion of non-europe area in the West. These phenomenon could be found out in connection with Acculturation, which means when two different cultures or more were contacted they were identified or merged in process of diffusion and change of them. This point of view was the culture anthropologic one that make a comparison and analysis of sameness and difference between cultures. The purpose of this study was to illuminate exotic taste represented in costume in the cluture-anthroplogic aspect, to compare with beauty of costume that each culture of costume and the meaning of the times due to those differences. an aspect of the exotic taste and character in the western costume that was inspected by dividing into 'Primitivism', 'Oriental element' and 'the element of a national costume in the East European bloc ' were as follows; First, Primitivism had something in common with what was pursued in the trend of Modern Art, through the late 19th century to the early 20th century. In fashion fettered by technique, the creation expressed in a free was and showed simple beauty of costume. At the same time, pure emotion expression, creative power and witty strong expression give the cognition of transcendency breaking the routine and the cognition of complexity of an included conception. Those are garments showing not only the primitive thought and mysticism but a fancy, an abstraction, and a life. Colors and accessaries which described nature and matched simple costume composition to the expression of various material or patterns transmitted the image of the primitive strongly. Second, "Drental element" which had an effect on western custome historically in a long time had outstanding luxurios adornmental beauty of custome. Extending from the Arab stated India, China, Korea, Japan, each national costume with a gay national culture became one of motif. Various ornamental factors expressed on Trapez Line, Sime Line and Drape, or Raied style, which did not restrict the body. Those were not only functional Easy Look, but were also satisfying human's ornamental desire. Third, national factors in the East European bloc are theme that begins to be embossed in the late 80's. In view of a political change and cultural situation with a double character of Europe and Orient, it was estimated that national factors have great importance in fashion. Item concerned with new concern appeared at Autumn & Winter collection. It shows elegant and graceful beauty of costume by adding a fur or jewel to simple form. These national factors in the East European bloc are simple form, but shows the difference in more cubic formation than form expressed in Primitivism or Oriental factors Exotic taste appeared form 80's to 91's, is thought to create an forgotten romantic emotion and traditional fashion

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A Study on the Efficient Management Plan of Water Distribution Reservoirs Facility Using 3D Geospatial Information (3D 공간정보를 이용한 배수지시설물의 효율적인 관리방안에 관한 연구)

  • Jung, In Hun;Ro, Young Suk;Choi, Yun Soo;Woo, Sang Yoon;Kim, Chong Mun
    • Spatial Information Research
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    • v.20 no.6
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    • pp.109-118
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    • 2012
  • Recent increasement of metropolitan infrastructure due to rapid expansion and development of urban areas which caused complexity and diversification of management system demands higher cost and effort to manage and maintain the facilities. The reason why it requires continuous and systematic management by national government is that the infrastructure facilities takes important role as it is directly related to public's living. Thus this study suggests an efficient management plan for increasement of work efficiency, cost reduction, and time saving by introducing 3D geospatial information system for water distribution reservoirs which is managed by the Office of Waterworks Seoul Metropolitan Government. This study evaluates and quantifies the range of work improvement using the 3D GIS technology through carrying out a survey targeting people in charge of the Office of Waterworks Seoul Metropolitan Government and other 8 offices. From the result of the research, applying the 3D-GIS improves by 90.32%, 93.55%, and 91.61% in the area of work efficiency, cost reduction, and time saving respectively. Consequently, using 3D GIS in future management of infrastructure could be used as a way of producing base data which supports administrative decision making through statistical and case analysis based on continuous data management. Also it would contribute to improving work efficiency by improving management system through preventing data omission.

A Study on Automatic Generation of Interface Circuits Based on FSM between Standard Buses and Ips (FSM을 이용한 표준화된 버스와 IP간의 인터페이스 회로 자동생성에 관한 연구)

  • Lee, Ser-Hoon;Moon, Jong-Uk;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.2A
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    • pp.137-146
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    • 2005
  • IP-based design methodology has been popularly employed for SoC design to reduce design complexity and to cope with time-to-market pressure. Interface modules for communication between system buses and IPs are required, since many IPs employ different protocols. Automatic generation of these interface modules would enhance designer's productivity and IP's reusability. This paper proposes an automatic interface generation system based on FSM generated from the protocol description of IPs. The proposed system provides the library modules for the standard buses to reduce the burdens of describing the protocols for data transfer from/to standard buses. Experimental results show that the area of the interface circuits generated by the proposed system had been increased slightly by 4.5% on the average when compared to manual designs. In the experiment, where bus clock is 100 Mhz and slave module clock is 34 Mhz, the latency of the interface had been increased by 7.1% in burst mode to transfer 16 data words. However, occupation of system bus can be reduce by 64.9%. A chip designer can generate an interface that improves the efficiency of system bus, by using this system.

Development of a Fire Human Reliability Analysis Procedure for Full Power Operation of the Korean Nuclear Power Plants (국내 전출력 원전 적용 화재 인간신뢰도분석 절차 개발)

  • Choi, Sun Yeong;Kang, Dae Il
    • Journal of the Korean Society of Safety
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    • v.35 no.1
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    • pp.87-96
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    • 2020
  • The purpose of this paper is to develop a fire HRA (Human Reliability Analysis) procedure for full power operation of domestic NPPs (Nuclear Power Plants). For the development of fire HRA procedure, the recent research results of NUREG-1921 in an effort to meet the requirements of the ASME/ANS PRA Standard were reviewed. The K-HRA method, a standard method for HRA of a domestic level 1 PSA (Probabilistic Safety Assessment) and fire related procedures in domestic NPPs were reviewed. Based on the review, a procedure for the fire HRA required for a domestic fire PSA based on the K-HRA method was developed. To this end, HRA issues such as new operator actions required in the event of a fire and complexity of fire situations were considered. Based on the four kinds of HFE (Human Failure Event) developed for a fire HRA in this research, a qualitative analysis such as feasibility evaluation was suggested. And also a quantitative analysis process which consists of screening analysis and detailed analysis was proposed. For the qualitative analysis, a screening analysis by NUREG-1921 was used. In this research, the screening criteria for the screening analysis was modified to reduce vague description and to reflect recent experimental results. For a detailed analysis, the K-HRA method and scoping analysis by NUREG-1921 were adopted. To apply K-HRA to fire HRA for quantification, efforts to modify PSFs (Performance Shaping Factors) of K-HRA to reflect fire situation and effects were made. For example, an absence of STA (Shift Technical Advisor) to command a fire brigade at a fire area is considered and the absence time should be reflected for a HEP (Human Error Probability) quantification. Based on the fire HRA procedure developed in this paper, a case study for HEP quantification such as a screening analysis and detailed analysis with the modified K-HRA was performed. It is expected that the HRA procedure suggested in this paper will be utilized for fire PSA for domestic NPPs as it is the first attempt to establish an HRA process considering fire effects.

A small-area implementation of public-key cryptographic processor for 224-bit elliptic curves over prime field (224-비트 소수체 타원곡선을 지원하는 공개키 암호 프로세서의 저면적 구현)

  • Park, Byung-Gwan;Shin, Kyung-Wook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.6
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    • pp.1083-1091
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    • 2017
  • This paper describes a design of cryptographic processor supporting 224-bit elliptic curves over prime field defined by NIST. Scalar point multiplication that is a core arithmetic function in elliptic curve cryptography(ECC) was implemented by adopting the modified Montgomery ladder algorithm. In order to eliminate division operations that have high computational complexity, projective coordinate was used to implement point addition and point doubling operations, which uses addition, subtraction, multiplication and squaring operations over GF(p). The final result of the scalar point multiplication is converted to affine coordinate and the inverse operation is implemented using Fermat's little theorem. The ECC processor was verified by FPGA implementation using Virtex5 device. The ECC processor synthesized using a 0.18 um CMOS cell library occupies 2.7-Kbit RAM and 27,739 gate equivalents (GEs), and the estimated maximum clock frequency is 71 MHz. One scalar point multiplication takes 1,326,985 clock cycles resulting in the computation time of 18.7 msec at the maximum clock frequency.