• Title/Summary/Keyword: 부분공간법

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Analyses of User Behavior and Preference Factors in the Outdoor Spaces of Psychiatric Hospitals (정신병원 옥외공간의 이용행태 및 선호요인 분석)

  • Ahn, Deug-Soo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.6
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    • pp.72-88
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    • 2014
  • This study was conducted in order to analyze user behavior and preference factors in the outdoor spaces of mental hospitals. Among hospitals with 250 or more beds, 5 hospitals were selected in consideration of size of garden and diversity of garden elements. The subject of the study was restricted to mild cases of schizophrenia while 30~50 patients were selected on the recommendation of their doctor from 5 hospitals, respectively. The physical environment was analyzed, focusing on space components, after visiting the sites of study. A face to face interview method was selected in consideration of patients' cognitive abilities, a total of 230 questionnaires were used for the analysis. The results of the study can be summarized as follows. Rest facilities occupy the largest numbers in the components of garden, and those are followed by landscape facilities, walking/exercise facilities, and experience facilities. Outdoor walking/exercise programs are classified into group walks and free walks with most patients taking group walks. Most of the patients visit these outdoor spaces every day but some of them rarely use the outdoor areas. In order to increase the efficiency of using these outdoor spaces, the percentage of space for ensuring a sense of control should properly harmonize with the percentage of space to facilitate patients in having social contact. With regard to the reasons for preferring the most widely-used outdoor spaces, landscape/environment property was the most important, followed by functionality and then accessibility. Major activities in the preferred space are mainly composed of walking/exercise and rest. The preferred facilities are waterscape facilities such as ponds, waterfalls and fountains, rest facilities such as pergolas and shade trees, and lawn. It was understood that naturalness should be considered to be the most important factor in constructing a new healing garden, followed by aesthetics and amenities. Single facilities rated by preference for introduction were flower beds, trails, and lawn. According to type, waterscape facilities such as fountains, ponds, waterfalls and waterwheels were most preferred. Space for natural distraction and programs for the cultivation of flower beds were also preferred. The ideal image of a healing garden should be bright, familiar, and orderly as a whole, having plenty of introduced facilities. Open spaces were preferred to enclosed spaces. Finally, the image of a garden that helps patients feel calm was thought to be that of the most ideal garden.

Sampling-based Approach for Seismic Probabilistic Risk Assessment (지진 확률론적 리스크 평가를 위한 샘플링기반 접근법)

  • Kwag, Shinyoung;Eem, Seunghyun;Park, Junhee;Choi, In-Kil
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.33 no.2
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    • pp.129-136
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    • 2020
  • In this study, we develop a sampling-based seismic probabilistic risk assessment (SPRA) quantification technique that can accurately consider a partially dependent condition of component seismic fragility information. Specifically, the SPRA quantification method is proposed by combining the advantages of two representative methodologies: EPRI seismic fragility and JAERI seismic fragility input-based quantification. The most important feature of the proposed method is that it performs a SPRA using a sampling technique by transforming the EPRI seismic fragility input into JAERI seismic fragility input. When the proposed sampling-based approach was applied to an example of simple system and to a SPRA problem of a nuclear power plant, it was observed that the proposed method yields approximately similar system seismic fragility and seismic risk results as those of the exact solution. Therefore, it is believed that the approach proposed in this study can be used as a useful tool for accurately assessing seismic risks, considering the partial seismic dependence among the components; the existing SPRA method cannot handle such partial dependencies.

Deformation of segment lining and behavior characteristics of inner steel lining under external loads (외부 하중에 따른 세그먼트 라이닝 변형과 보강용 내부 강재 라이닝의 거동 특성)

  • Gyeong-Ju Yi;Ki-Il Song
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.26 no.3
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    • pp.255-280
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    • 2024
  • If there are concerns about the stability of segment lining due to section deficiency or large deformation in shield TBM tunnel, reinforcement can be done through ground grouting outside the tunnel or by using steel plate reinforcement, ring beam reinforcement, or inner double layer lining inside the tunnel. Traditional analyses of shield TBM tunnels have been conducted using a continuum method that does not consider the segmented nature of segment lining. This study investigates the reinforcement mechanism for double layer reinforced sections with internal steel linings. By improving the modeling of segment lining, this study applies Break-joint mode (BJM), which considers the segmented characteristics of segment lining, to analyze the deformation characteristics of double layer reinforced sections. The results indicate that the existing concrete segment lining functioned similarly to ground reinforcement around the tunnel, rather than distribution the load. In general, both the BJM model considering the segmentation of segment lining and the continuum rigid method were similar deformation shapes and stress distributions of the lining under load. However, in terms of deformation, when the load strength exceeded the threshold, the deformation patterns of the two models differed.

Single Degree of Freedom Hybrid Dynamic Test with Steel Frame Structure (강 뼈대 구조물의 단자유도 하이브리드 동적 실험)

  • Kim, Se-Hoon;Na, Ok-Pin;Kim, Sung-Il;Lee, Jae-Jin;Kang, Dae-Hung
    • Journal of the Korean Society for Railway
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    • v.15 no.4
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    • pp.413-421
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    • 2012
  • The purpose of this study is to evaluate the structural dynamic behavior under hybrid control system. The hybrid test is to consider the interaction between the numerical and physical models. In this paper, single degree of freedom hybrid test was performed with one-bay, two-story steel frame structure. One column at the first floor was selected as a physical substructure and one actuator was used for applying the displacement load in horizontal direction. El Centro as earthquake waves was inputted and OpenSees was employed as the numerical analysis program for the hybrid real-time simulation. As a result, the total time of the hybrid test was about 9.6% of actual measured seismic period. The experimental results agreed well with the numerical one in terms of the maximum displacement. In nonlinear analysis, however, material nonlinearity made a difference of residual strain. Therefore, this hybrid dynamic test can be used to predict the structural dynamic performance more effectively than shaking table test, because of the spatial and economic limitations.

An Experimental Study About a Net-Type External Prestress Strengthening Method for Slab Bridges (네트형 외부 긴장재에 의한 슬래브교 보강 실험)

  • Han, Man Yop;Kang, Tae Heon;Choi, Sok Hwan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.5
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    • pp.136-149
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    • 2011
  • Large portion of the domestic bridges are slab bridges reflecting the geographical characteristic of the country, where exists lots of inclines and small winding brooks. Many of the slab bridges are damaged and superannuated as they become obsolete. Deterioration is accelerated when the traffic density becomes large and heavy vehicles pass frequently. A strengthening method for deteriorated slab bridges was studied in this work. The examined net-type strengthening method uses both longitudinal and transverse prestressing for strengthening. In this way, the deflection at the center of the slab can be better controlled, and consequently, the slab is more efficiently strengthened. Three slab specimens were fabricated for the experimental test and subjected to three different loading conditions, and the load bearing capacities and deflections of slabs were examined. Flexural stiffness of slabs increased by 30.7~107.3%, and deflection of slabs decreased by 27.6~52.2% after net-type strengthening. The net-type prestressing is efficient to the strengthening for the center of a slab, and its efficiency is also valid under eccentric loadings. Since extra prestress forces can be added in the future, if necessary, the net-type strengthening system is advantagous for the maintenance and repair of slab bridges.

The Evaluation of Reconstructed Images in 3D OSEM According to Iteration and Subset Number (3D OSEM 재구성 법에서 반복연산(Iteration) 횟수와 부분집합(Subset) 개수 변경에 따른 영상의 질 평가)

  • Kim, Dong-Seok;Kim, Seong-Hwan;Shim, Dong-Oh;Yoo, Hee-Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.17-24
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    • 2011
  • Purpose: Presently in the nuclear medicine field, the high-speed image reconstruction algorithm like the OSEM algorithm is widely used as the alternative of the filtered back projection method due to the rapid development and application of the digital computer. There is no to relate and if it applies the optimal parameter be clearly determined. In this research, the quality change of the Jaszczak phantom experiment and brain SPECT patient data according to the iteration times and subset number change try to be been put through and analyzed in 3D OSEM reconstruction method of applying 3D beam modeling. Materials and Methods: Patient data from August, 2010 studied and analyzed against 5 patients implementing the brain SPECT until september, 2010 in the nuclear medicine department of ASAN medical center. The phantom image used the mixed Jaszczak phantom equally and obtained the water and 99mTc (500 MBq) in the dual head gamma camera Symbia T2 of Siemens. When reconstructing each image altogether with patient data and phantom data, we changed iteration number as 1, 4, 8, 12, 24 and 30 times and subset number as 2, 4, 8, 16 and 32 times. We reconstructed in reconstructed each image, the variation coefficient for guessing about noise of images and image contrast, FWHM were produced and compared. Results: In patients and phantom experiment data, a contrast and spatial resolution of an image showed the tendency to increase linearly altogether according to the increment of the iteration times and subset number but the variation coefficient did not show the tendency to be improved according to the increase of two parameters. In the comparison according to the scan time, the image contrast and FWHM showed altogether the result of being linearly improved according to the iteration times and subset number increase in projection per 10, 20 and 30 second image but the variation coefficient did not show the tendency to be improved. Conclusion: The linear relationship of the image contrast improved in 3D OSEM reconstruction method image of applying 3D beam modeling through this experiment like the existing 1D and 2D OSEM reconfiguration method according to the iteration times and subset number increase could be confirmed. However, this is simple phantom experiment and the result of obtaining by the some patients limited range and the various variables can be existed. So for generalizing this based on this results of this experiment, there is the excessiveness and the evaluation about 3D OSEM reconfiguration method should be additionally made through experiments after this.

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Development of Quality Control Method for Visibility Data Based on the Characteristics of Visibility Data (시정계 자료 특성을 고려한 시정계 자료 품질검사 기법 개발)

  • Oh, Yu-Joo;Suh, Myoung-Seok
    • Korean Journal of Remote Sensing
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    • v.36 no.5_1
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    • pp.707-723
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    • 2020
  • In this study, a decision tree type of quality control (QC) method was developed to improve the temporal-spatial representation and accuracy of the visibility data being operated by the Korea Meteorological Administration (KMA). The quality of the developed QC method was evaluated through the application to the 3 years (2016.03-2019.02) of 290 stations visibility data. For qualitative and quantitative verification of the developed QC method, visibility and naked-eye data provided by the KMA and QC method of the Norwegian Meteorological Institute (NMI) were used. Firstly, if the sum of missing and abnormal data exceeds 10% of the total data, the corresponding point was removed. In the 2nd step, a temporal continuity test was performed under the assumption that the visibility changes continuously in time. In this process, the threshold was dynamically set considering the different temporal variability depending on the visibility. In the 3rd step, the spatial continuity test was performed under the assumption of spatial continuity for visibility. Finally, the 10-minute visibility data was calculated using weighted average method, considering that the accuracy of the visibility meter was inversely proportional to the visibility. As results, about 10% of the data were removed in the first step due to the large temporal-spatial variability of visibility. In addition, because the spatial variability was significant, especially around the fog area, the 3rd step was not applied. Through the quantitative verification results, it suggested that the QC method developed in this study can be used as a QC tool for visibility data.

A Study on the Aviation Case Law -Focusing on the Application of Treaties for the International Carriage by Air- (항공판례의 연구 -국제항공운송조약의 적용문제를 중심으로-)

  • Kim, Jong-Bok
    • The Korean Journal of Air & Space Law and Policy
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    • v.21 no.1
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    • pp.29-63
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    • 2006
  • This paper studied and introduced the aviation law cases in applying the treaties of the Warsaw System to the liability of the international air carrier by categorizing four main sections. Firstly, this paper handled the cases regarding the defining an international flight, exclusivity of the treaties as international air carrie's liability Convention, determining treaty relationship between the countries which one country has ratified only the Hague Protocol, an amended version of the Warsaw Convention, while the other has ratified only the original, unamended Warsaw Convention. Annotation assisted the case if it needed. Secondly, the cases relating to the issues of actual and contracting carrier, successive carrier, agents and servants of the carrier and others were studied. Thirdly, the issues relating to the accident in the course of any operations of embarking or disembarking of passengers, the occurrence during the transportation by air of baggage or goods and delay in the transportation by air of passengers, baggage or goods in addition to the cancellation of the flights were studied according to the applicable range. Fourthly, I studied the time issue with effective date of the treaties. Conclusively, it is not excessive to emphasize the importance of cases in Aviation Law like all other legal areas, therefore, a full-dress future reaserch of aviation cases is expected in here Korea with this paper as a foundation although it studied and introduced only a part of numerous aviation law cases.

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The Trend of Aviation Terrorism in the 4th Industrial Revolution Period and the Development Direction for Domestic Counter Terrorism of Aviation (제4차 산업혁명 시대의 항공 테러리즘 양상 및 국내 항공테러 대응체계 발전방향)

  • Hwang, Ho-Won;Kim, Seung-Woo
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.2
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    • pp.155-188
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    • 2017
  • On the one hand, the 4th Industrial Revolution provides a positive opportunity to build a new civilization paradigm for mankind. However, on the other hand, due to the 4th Industrial Revolution, artificial intelligence such as 'Goggle Alpha Go' revolutionized and even the human ability was replaced with a 'Silicon Chip' as the opportunity to communicate decreases, the existence of human beings is weakened. And there is a growing concern that the number of violent crimes, such as psychopath, which hunts humans as games, will increase. Moreover, recent international terrorism is being developed in a form similar to 'Psychopathic Violent-Crime' that indiscriminately attacks innocent people. So, the probability that terrorist organizations abuse the positive effects provided by the Fourth Industrial Revolution as means of terrorism is increasing. Therefore, the paradigm of aviation terrorism is expected to change in a way that attacks airport facilities and users rather than aircraft. Because airport facilities are crowded, and psychopathic terrorists are easily accessible. From this point of view, our counter terrorism system of aviation has many weak points in various aspects such as: (1) limitations of counter-terrorism center (2) inefficient on-site command and control system (3) separated organization for aviation security consultation (4) dispersed information collection function in government (5) vulnerable to cyber attack (6) lack of international cooperation network for aviation terrorism. Consequently, it is necessary to improve the domestic counter terrorism system of aviation so as to preemptively respond to the international terrorism. This study propose the following measures to improve the aviation security system by (1) create 'Aviation Special Judicial Police' (2) revise the anti-terrorism law and aviation security law (3) Strengthening the ability respond to terrorism in cyberspace (4) building an international cooperation network for aviation terrorism.

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A Fast Search Algorithm for Raman Spectrum using Singular Value Decomposition (특이값 분해를 이용한 라만 스펙트럼 고속 탐색 알고리즘)

  • Seo, Yu-Gyung;Baek, Sung-June;Ko, Dae-Young;Park, Jun-Kyu;Park, Aaron
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.12
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    • pp.8455-8461
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    • 2015
  • In this paper, we propose new search algorithms using SVD(Singular Value Decomposition) for fast search of Raman spectrum. In the proposed algorithms, small number of the eigen vectors obtained by SVD are chosen in accordance with their respective significance to achieve computation reduction. By introducing pilot test, we exclude large number of data from search and then, we apply partial distance search(PDS) for further computation reduction. We prepared 14,032 kinds of chemical Raman spectrum as the library for comparisons. Experiments were carried out with 7 methods, that is Full Search, PDS, 1DMPS modified MPS for applying to 1-dimensional space data with PDS(1DMPS+PDS), 1DMPS with PDS by using descending sorted variance of data(1DMPS Sort with Variance+PDS), 250-dimensional components of the SVD with PDS(250SVD+PDS) and proposed algorithms, PSP and PSSP. For exact comparison of computations, we compared the number of multiplications and additions required for each method. According to the experiments, PSSP algorithm shows 64.8% computation reduction when compared with 250SVD+PDS while PSP shows 157% computation reduction.