• Title/Summary/Keyword: AIR 모델

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Services of an Integrated Simulation Engine for Weapons Analysis (무기체계 효과도 분석을 위한 통합 모의 엔진의 서비스 구성 방안 연구)

  • Kim, Tae-Sup;Park, Joon-Ho;Kim, Hyun-Hwi;Park, Chan-Jong;Lee, Kang-Sun
    • Journal of the Korea Society for Simulation
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    • v.19 no.4
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    • pp.261-270
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    • 2010
  • An integrated simulation engine provides tools, services, and standards to support various activities in the entire M&S from modeling and simulation to analysis of the simulation results. Many countries have developed integrated simulation engines to efficiently assist complex M&S activities. However, we do not have domestic simulation engines especially designed for defense M&S, therefore, developing M&S softwares still remains as a hard task with high cost and tine. OpenSIM(Open Simulation engine for Interoperable Models) is an integrated simulation engine and provides tools, services and standard interfaces for weapons analysis. OpenSIM's services are comprised of classes, member functions and data attributes which are commonly used in modeling, simulating and analyzing weapons systems. In this paper, we introduce OpenSIM's services in C++ APIs and illustrate them through an ASM example(Air to Surface Missile).

Estimation of Unsaturated Permeability Function from Water Retention Characteristics for Korean Weathered Soils (함수특성에 근거한 국내 풍화토의 불포화 투수곡선 추정)

  • Kim, Yun-Ki;Choi, Kyung-Lim;Lee, Sung-Jin;Lee, Seung-Rae;Kwon, Hyoung-Seok
    • Journal of the Korean Geotechnical Society
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    • v.26 no.10
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    • pp.49-60
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    • 2010
  • Unsaturated permeability function is an important factor in the design and analysis of various unsaturated soil structures. Generally the permeability characteristics decrease as the mat ric suction increases and the trend is similar to water retention characteristics of a soil. The permeability of unsaturated soils can be obtained directly by laboratory tests or indirectly by estimation methods from other soil properties. For unsaturated soils sampled from 7 areas in KOREA, SWCCs and unsaturated permeability functions were obtained by experimental tests. The unsaturated permeability results were also compared with the unsaturated permeability functions derived from the SWCCs theoretically. However, the current estimation models of unsaturated permeability function did not express the unsaturated permeability characteristics. Therefore, the FXK-M permeability function was modified to predict more accurate permeability functions for Korean weathered soils using a correction factor that can be calculated from the air-entry value of SWCC. The new estimation model resulted in good agreements for all tested soils.

Comparison of the Free-Fall Impact Force Applied to a Multicopter PAV According to External Airbag Folding Method (외부 에어백 폴딩 방식에 따른 자유 낙하 충돌 시 멀티콥터형 개인용 항공기에 가해지는 충격력 비교)

  • Jang, Yoon Ho;Kim, Jeong
    • Journal of Aerospace System Engineering
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    • v.16 no.1
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    • pp.28-39
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    • 2022
  • With the development of small multicopter PAV (Personal Air Vehicle), it is necessary to develop safety-related devices for manned rotorcraft. In this study, we assumed that an external airbag can be installed in a small multicopter PAV, and using LS-DYNA's Airbag Folding Application, we performed a free-fall collision analysis by modeling the airbag shapes consisting or Roll, Zigzag, and Sigma. There was no significant difference in the final airbag deployment time of the three models. However, when it collides with the ground during deployment, the Sigma fold type external airbag had the fastest deployment speed, applying the most impact force to the PAV, while the Roll fold type external airbag applied the smallest impact force to the PAV.

The Tentative Plans of Middle-rise Traditional Houses (Han-ok) Located on Seoun-dong in Urban Area of Cheongju, Korea (중층형 생활한옥 모델시안 연구 - 청주 서운동의 사례를 중심으로 -)

  • Kim, Chan Gu;Kim, Tai Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.2
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    • pp.21-28
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    • 2022
  • Focusing on the creation of a new han ok, especially a mid-rise hybrid-structured Han-ok, this study proposes a middle-rise (four-story) Han-ok on one and two lots located in Seoun-dong, the existing Han-ok intensive housing site in downtown Cheongju. 1) In terms of layout and function, according to the existing L-shaped Han-ok corresponding to the road and the direction, the parking lots and shops on the 1st floor, the business facility on the 2nd floor, the Han-ok on the 3rd and 4th floors are placed. There are yards, open roof yards, and semi-open Daecheong(大廳, main hall), which can be shared by residents. 2) In terms of structure and form, one or two floors (some 3 floors) are 5.4m square and 5.4×6.6m modules of the RC(Reinforced Concrete) group, and the upper floor reflects the 2.7m module, size and shape of the existing Han-ok. By extending the outer wall of the RC group in the lower floors (1st to 3rd floors) to the wooden exterior of the upper floors (2nd to 4th floors), it is attempted to avoid the awkward appearance of the RC group being exposed to wooden structures. And it is also attempted to reflect the wooden shape and design elements through the elevation elements such as horizontal windows, corner windows, picture frames, and vertical slits. 3) In environmental control and facilities, it is attempted to smooth the ventilation of the building by forming a vertical upward airflow from the dark space of the low floor to the positive of the upper floor. This doubles the effect through a vertical rise of cold air generated in a narrow alleyway, piloti parking lot, and the various voids. In addition to the Daecheong and Numaru(loft) of Han ok, the rooftop yard, the terrace, and the balcony, horizontal natural ventilation is generated through divided doors and transom windows.

Identification of Void Diameters for Cast-Resin Transformers (몰드변압기의 보이드 결함 크기 판별)

  • Jeong, Gi-woo;Kim, Wook-sung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.10a
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    • pp.570-573
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    • 2022
  • This paper presents the identification of void diameters for a cast-resin transformer using an artificial neural network (ANN) model. A PD signal was measured by the Rogowski coil sensor which has the planar and thin structures fabricated on a printed circuit board (PCB), and the PD electrode system was fabricated to simulate a PD defect by a void. In addition, void samples with different diameters were fabricated by injecting air in a cylindrical aluminum frame using a syringe during the epoxy curing process. To identify the diameter of void defects, PD characteristics such as the discharge magnitude, pulse count, and phase angle were extracted and back propagation algorithm (BPA) was designed using virtual instrument (VI) based on the Labview program. From the experimental results, the BPA algorithm proposed in this paper has over 90% accurate rate to identify the diameter of void defects and is expected to use reference data of maintenance and replacement of insulation for cast-resin transformers in the on-site PD measurement.

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A Study on the Design of Digital Twin-Based Communication Tools for Smart Port and Autonomous Ship (스마트항만-자율운항선박 연계를 위한 디지털 트윈 기반 커뮤니케이션 도구 설계 연구)

  • Cho Yuseong;Cho Yongdeok;Koo Hanmo;Koopo Kwon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2022.11a
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    • pp.362-365
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    • 2022
  • With the development of the 4th industrial revolution technology, smartization in various fields is accelerating. The shipping and logistics industry is also promoting smartization by combining advanced new technologies such as digital twin, Internet of Things, and artificial intelligence. In Korea, the Ministry of Maritime Affairs and Fisheries is promoting a strategy to spread the smart shipping logistics system in line with the changing global shipping logistics trend, and through this, it is creating a foundation for smart shipping logistics. This study aims to present the concept of a communication tool that recognizes the importance of communication between each logistics entity and exchanges opinions between logistics entities in a virtual digital twin environment to cope with the changing shipping logistics process. In addition, for the development of these communication tools, this study derive a software design model, including architecture.

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A Study on Auto-Classification of Aviation Safety Data using NLP Algorithm (자연어처리 알고리즘을 이용한 위험기반 항공안전데이터 자동분류 방안 연구)

  • Sung-Hoon Yang;Young Choi;So-young Jung;Joo-hyun Ahn
    • Journal of Advanced Navigation Technology
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    • v.26 no.6
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    • pp.528-535
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    • 2022
  • Although the domestic aviation industry has made rapid progress with the development of aircraft manufacturing and transportation technologies, aviation safety accidents continue to occur. The supervisory agency classifies hazards and risks based on risk-based aviation safety data, identifies safety trends for each air transportation operator, and conducts pre-inspections to prevent event and accidents. However, the human classification of data described in natural language format results in different results depending on knowledge, experience, and propensity, and it takes a considerable amount of time to understand and classify the meaning of the content. Therefore, in this journal, the fine-tuned KoBERT model was machine-learned over 5,000 data to predict the classification value of new data, showing 79.2% accuracy. In addition, some of the same result prediction and failed data for similar events were errors caused by human.

A Numerical Method for Analysis of the Sound and Vibration of Waveguides Coupled with External Fluid (외부 유체와 연성된 도파관의 진동 및 소음 해석 기법)

  • Ryue, Jung-Soo
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.7
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    • pp.448-457
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    • 2010
  • Vibrations and wave propagations in waveguide structures can be analysed efficiently by using waveguide finite element (WFE) method. The WFE method only models the 2-dimensional cross-section of the waveguide with finite elements so that the size of the model and computing time are much less than those of the 3-dimensional FE models. For cylindrical shells or pipes which have simple cross-sections, the external coupling with fluids can be treated theoretically. For waveguides of complex cross-sectional geometries, however, numerical methods are required to deal with external fluids. In this numerical approach, the external fluid is modelled by the boundary elements (BEs) and connected to WFEs. In order to validate this WFE/BE method, a pipe submerged in water is considered in this study. The dispersion diagrams and point mobilities of the pipe simulated are compared to those that theoretically obtained. Also the acoustic powers radiated from the pipe are predicted and compared in both cases of air and water as an external medium.

A study on the acoustic performance of an absorptive silencer applying the optimal arrangement of absorbing materials (흡음재 최적 배치를 적용한 흡음형 소음기의 음향성능 연구)

  • Dongheon Kang;Haesang Yang;Woojae Seong
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.3
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    • pp.261-269
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    • 2024
  • In this paper, the acoustic performance of an absorptive silencer was enhanced by optimizing an arrangement of multi-layered absorbing materials. The acoustic performance of the silencer was evaluated through transmission loss, and finite element method-based numerical analysis program was employed to calculate the transmission loss. Polyurethane, a porous elastic material frequently used in absorptive silencers, was employed as the absorbing material. The Biot-Allard model was applied, assuming that air is filled inside the polyurethane. By setting the frequency range of interest up to the 2 kHz and the acoustic performance affecting properties of the absorbing materials were investigated when it was composed as a single layer. And the acoustic performance of the silencers with the single and multi-layered absorbing materials was compared with each other based on polyurethane material properties. Subsequently, the arrangement of the absorbing materials was optimized by applying the Nelder-Mead method. The results demonstrated that the average transmission loss improved compared to the single-layered absorptive silencer.

Real-time Fault Detection System of a Pneumatic Cylinder Via Deep-learning Model Considering Time-variant Characteristic of Sensor Data (센서 데이터의 시계열 특성을 고려한 딥러닝 모델 기반의 공압 실린더 고장 감지 시스템 구현)

  • Byeong Su Kim;Geun Myeong Song;Min Jeong Lee;Sujeong Baek
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.47 no.2
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    • pp.10-20
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    • 2024
  • In recent automated manufacturing systems, compressed air-based pneumatic cylinders have been widely used for basic perpetration including picking up and moving a target object. They are relatively categorized as small machines, but many linear or rotary cylinders play an important role in discrete manufacturing systems. Therefore, sudden operation stop or interruption due to a fault occurrence in pneumatic cylinders leads to a decrease in repair costs and production and even threatens the safety of workers. In this regard, this study proposed a fault detection technique by developing a time-variant deep learning model from multivariate sensor data analysis for estimating a current health state as four levels. In addition, it aims to establish a real-time fault detection system that allows workers to immediately identify and manage the cylinder's status in either an actual shop floor or a remote management situation. To validate and verify the performance of the proposed system, we collected multivariate sensor signals from a rotary cylinder and it was successful in detecting the health state of the pneumatic cylinder with four severity levels. Furthermore, the optimal sensor location and signal type were analyzed through statistical inferences.