• Title/Summary/Keyword: 경험적 설계법

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The Simulator Study on Driving Safety while Driving through the Longitudinal Tunnel (차량시뮬레이터를 이용한 장대터널 주행안전성 연구)

  • Ryu, Jun-Beom;Sihn, Yong-Kyun;Park, Sung-Jin;Han, Ju-Hyun
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.149-156
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    • 2011
  • Considerable evaluation is needed to design a new longitudinal tunnel in advance because it damaged drivers' driving safety and heightened the possibility of traffic accidents with its physical characteristics. Specifically, considering traffic psychological and ergonomic factors was very important to prevent the difficulty of maintaining safe speed, the increase of the drowsy driving, the fatality of traffic accidents, and subjective feelings such as anxiety while driving a car through the tunnel, from design to construction. This study dealt with driving safety evaluation of an original road alignment design for the longitudinal tunnel (length: above 10km) with a driving simulator, and helped us to improve an original road alignment design and make an alternative road alignment design with presenting risky districts. The results of experiment showed that inflection points were revealed more risky districts, because they impaired driving safety and elevated driver workload while driving a car through around the inflection points of two-way route. Finally, the limitations and implications of this study were discussed.

Case study of the large switching software metrics and their fault analysis (대형 교환 소프트웨어의 복잡성과 고장분석 사례 연구)

  • 이재기;남상식;김창봉;이규대
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10C
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    • pp.887-901
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    • 2002
  • Software management model divided into the software project model and design estimation model, software matrices model, reliability growth model, process improvement model(or process maturity model) etc. Among these software management models, software complexity model make an estimated of the product software. For a practice of software managed, need to guideline of the static analysis of software. Especially, Software complexity model introduced for the estimation of software quantity and program complexity. In case of measurement the software matrices, its need for us to analysis of software quality and products. On the other hand, we known that complexity program include many defects and consuming of source cost. So, we apply to complexity model using of the program complexity, control structure and volume matrices, interface metrics, process complexity metrics method. In this paper, we represent that the analysis of fault data detected during the system test. Also, we analysis of program control structure and interface, volume matrices in various aspect of switching software. Others, their results utilized similar of project and system development.

Evaluation of Point Bearing Capacity using Field Model Pile Test (현장 축소모형 말뚝 시험을 이용한 선단지지력 예측)

  • Lee, Chang-Ho;Lee, Woo-Jin;Jeong, Hun-Jun;Han, Shin-In
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.3
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    • pp.47-54
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    • 2005
  • In many practical cases, design methods of pile have been used mainly semi empirical bearing capacity equations. It can be done that confirmation of pile bearing capacities through using of dynamic and static tests during constructing or after constructions. If a prediction of layered point pile bearing capacity could be done through simple tests during field investigation, it could be done that more reliable design of pile than a prediction of using semi empirical equations or static formulations. This paper suggests a method to estimated point bearing capacity during in-situ investigation by using the dynamic rod model pile and verifies the point bearing capacity compare with results of static pile load tests. From test results, the unit ultimate point bearing capacities are relatively similar through a dynamic rod model pile tests and static pile load tests. The unit ultimate point bearing capacity by using N value is shown about 50 % value of measured unit ultimate point bearing capacity from field test result and the prediction of the unit ultimate point bearing capacity by using N value is shown very conservative, illogical and uneconomical pile designs.

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A Study on the Applicability of Arias Intensity Liquefaction Assessment (Arias Intensity 액상화 평가기법의 적용성에 관한 연구)

  • Hwang, Jungtae;Lee, Jongkeun;Shin, Eunchul
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.6
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    • pp.13-19
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    • 2013
  • In this study, the target ground was selected for the assessment of liquefaction, for which energy-based Arias intensity liquefaction assessment method was applied, The results of evaluation by simplified method using conventional in-situ test were compared. The result of the assessment of liquefaction revealed that the safety factor of the Arias Intensity using the actual records of the Hachinohe and Ofunato earthquake showed generally similar trends with the simplified method, However, the Arias Intensity factor of safety for the artificial earthquake created from the design response spectrum showed some difference from the factors of safety of the simplified method. The shear stress ratio and the occurrence strength of the Arias Intensity are differently calculated between stress and energy, but the resistance stress ratio of the simplified method and the resistance strength of the Arias Intensity use the empirical chart of the results of the standard penetration test for the actual liquefaction areas by the earthquake, which seems the reason for the similar results between Arias Intensity assessment and stress concept simplified method for Hachinohe and Ofunato earthquakes. Therefore, it was found that the energy-based Arias Intensity liquefaction assessment could represent the dynamic changes of the ground caused by seismic characteristics such as acceleration, magnitude, duration and amplitude.

Equivalent Design Parameter Determination for Effective Numerical Modeling of Pre-reinforced Zones in Tunnel (터널 사전보강 영역의 효과적 수치해석을 위한 등가 물성치 결정 기법)

  • Song, Ki-Il;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.8 no.2
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    • pp.151-163
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    • 2006
  • Although various methods for effective modeling of pre-reinforced zones have been suggested for numerical analysis of large section tunnels, tunnel designers refer to empirical cases and literature reviews rather than engineering methods because ones who use commercial programs are unfamiliar with a macro-scale approach in general. Therefore, this paper suggests a simple micro-scale approach combined with the macro-scale approach to determine equivalent design parameters for effective numerical modeling of pre-reinforced zones in tunnel. This new approach is to determine the equivalent stiffness of pre-reinforced zones with combination of ground, bulb, and steel in series or/and parallel. For verification, 3-D numerical results from the suggested approach are compared with those of a realistic model. The comparison suggests that two cases make best approximation to a realistic solution: One is related to the series-parallel stiffness system (hereafter SPSS) in which bulb and steel are coupled in parallel and then connected to the ground in series, and the other is the series stiffness system (hereafter SSS) in which only bulb and steel are coupled in series. The SPSS is recommended for stiffness calculation of pre-reinforced zones because the SSS is inconvenient and time-consuming. The SPSS provides slightly bigger vertical displacement at tunnel crown in weathered rock than other cases and give almost identical results to a realistic model for horizontal displacement at tunnel spring line and ground surface settlement. Displacement trends on weathered rock and weathered soil are similar. The SPSS which is suggested in this paper represents the behavior mechanism of pre-reinforced area effectively.

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Comparison of FDTD Computed and Measured SAR of Hand-Held Mobile phone (FDTD 계산과 측정에 의한 휴대폰 SAR 비교)

  • 홍수원;오학태;박천식
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.7
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    • pp.1161-1167
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    • 2000
  • SAR 추정시스템에 사용되는 phantom의 FDTD 모델에 휴대폰을 병합시켜 측정시켜 추정시스템과 동일한 상황으로 구현하영 계산한 결과, 측정값과 오차 범위 ±10%내로 확인하였으며 또한, Om P. Gandhi의 결과 오차±20%를 개선하였다. 이로써 단지 경험에 의존하거나, 제품의 완성된계에서의 별개의 작업으로 SAR을 고려하는 것이 아니라, 설계 단계에서 정량적으로 SAR이 고려된 휴대폰을 개발할 수 있는 방법을 제안하였다. 즉, 제안된 방법을 이용하여 휴대폰의 통화품질 개선과 SAR 저감을 동시에 만족시키는 양질의 휴대폰 개발이 가능할 석으로 개대한다. 특히, 이방법은 새로운 휴대폰 개발에 소용되는 비용과 시간을 대폭 줄일 수 있는 장점이 있다.

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Simulation for Initial Motion of a Test Vehicle Launched from Sliding Launcher (활강 진수대에서 운용되는 시험용 운동체의 초기 거동 모사)

  • Yepmg-Il Park;Chan-Ki Kim;Sun-Hong Kwon;Man-Hyung Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.36 no.2
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    • pp.29-39
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    • 1999
  • In this study, mathematical modelling for initial motion of test vehicle launched from sliding launcher is performed, and simulation results from this mathematical models are verified by comparing them with sea trial results. Especially, it is showed that models using strip method give better results than using empirical formulae and linear equations of motion. This mathematical model can give useful tools to design sliding launchers or test vehicles.

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An automated neural network design from a well organized data set (정제된 데이터를 이용한 신경망의 설계 자동화에 관한 연구)

  • 백주현;김홍기
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.03a
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    • pp.53-56
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    • 1998
  • 본 논문에서의 공학적인 체계성을 갖고 초기 연결 가중치 및 임계치를 결정해 주면서, 학습까지 가능한 신경망을 제안한다. 기존의 오류 역전파 신경망을 적용할 때 경험에 의하여 은닉층 노드수를 결정하거나 임의의 실수 값으로 초기 연결 가중치 및 임계값을 주었을 때 자주 발생하는 학습 마비 현상을 피할 수 있고, Bose가 제안된 Voronoi 공간 분류에 의한 신경망 구성에서 학습이 불가능하다는 제안적인 단점을 보안하였다. 초기 가중치는 Voronoi 공간 분류가 이루어져 있다고 할 때 Bose가 제안한 초기 가중치 결정법을 개선하여 사용하고, Bose의 경우 신경망 노드가 Step function을 이용하여 정보를 전달하였으나 본 연구에서는 학습이 가능한 함수인 Sigmoid function을 이용하였다. 제안된 새로운 신경망의 성능 및 효율성을 비교하기 위하여 선형분리가 불가능한 XOR문제를 실험한 결과, 기존의 학습 가능한 EBP에서 허용오차 0.05 수준일 때 80%정도 학습마비 현상이 발생하였던 심각한 문제점을 보완할 수 있었고, 또한 학습 속도면에서 8~9배 정도 빠른 성능을 나타내었다.

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Implement and Design of Viewer System based on the Panoramic Virtual Reality (파노라마 가상현실을 기반으로 하는 뷰어 시스템 설계와 구현)

  • Kim, Chang-Ki;Hong, Sung-Soo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2013.05a
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    • pp.983-986
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    • 2013
  • 최근 남녀노소를 불문하고 컴퓨터를 활용한 일상생활의 편리함은 누구나 알고 있는 사실이며, 현대인의 바쁜 일상은 보다 나은 효율적인 생활을 추구하고 있다. 또한, 특정 장소에 가보지 않고 그곳을 컴퓨터를 통해 간단한 조작으로 가상의 공간을 탐색하여 비용과 시간을 절약 할 수 있는 장점이 있다. 따라서 본 논문에서는 파노라마 가상현실(panoramic virtual reality)을 이용해 보다 편리한 가상 세계의 탐색의 경험을 도운다. 가상현실을 구성하는 장면을 구성하는 이미지의 스티칭, 편집 그리고 가상머신의 이용법, 핫스팟을 통한 장소와 장소간의 상호작용에 대해서 소개한다.

A Case Study on application of Action Learning in Basic Nursing Science: by Contents Analysis of the Reflection Journals (기초간호과학 수업에서 액션러닝 적용 사례연구 : 성찰일지 내용분석 중심으로)

  • Joo, Eun-Kyung
    • Journal of Digital Convergence
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    • v.19 no.8
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    • pp.397-404
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    • 2021
  • The aim of this study is to explore the educational experience of nursing students after designing an action learning class suitable for basic nursing science class and applying it. A total 100 freshmen nursing students taking a basic nursing science class of K university in S city participated in this study. Data was collected from May 2019 to June 2020. The action learning class consisted of 5-6 people per team, a total of 9 teams, reflection diaries were collected and analyzed using the qualitative content analysis method of Krippendorff (2004). The analysis produced 45 significant statements in total, 8 themes and 4 categries for the experience of basic nursing science class based on action learning. The 4 categories were 'confidence in anatomy', 'growing teamwork', 'learned how to study', 'difficulties in the process'. The action learning applied class was found to be effective in problem-solving ability, teamwork, and self-directed learning. Therefore, it is proposed to evaluate the effect of action learning in other nursing subjects as well.