• 제목/요약/키워드: hazard function

검색결과 404건 처리시간 0.027초

숲가꾸기 산물의 이동특성 분석을 위한 기초연구 (A Basic Study for Analysis of Moving Characteristics of Thinning Slash)

  • 전계원;이호진;연규방
    • 한국방재학회:학술대회논문집
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    • 한국방재학회 2008년도 정기총회 및 학술발표대회
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    • pp.719-722
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    • 2008
  • Forest management is done to keep ecological health of forest and to enhancement of its function. Nowadays, the abnormal climate and heavy rain happen frequently. Therefore, there are opinions that the thinning slash allowed in the mountain is flowed in rivers, which can influence in flood damage. This study, we grasp moving characteristics of thinning slash through field survey and achieved basic study about the effect of thinning slash on the discharge capacity of rivers and stream structure.

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컨테이너 크레인의 생산성 향상에 관한 연구 (On the Study of the Production Improvement of Container Cranes)

  • 손정기
    • 한국항만학회지
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    • 제12권1호
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    • pp.113-118
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    • 1998
  • The Container crane is mainly used in the harbor. But in spite of this wide use, it is a fact that there are still areas for automation, concerning the operator and the control system. If the encoding function is enhanced, then control effect can be increased to some extent. Since the distance from the hoist to the trolley cam be measured, the moving distance from the loading and unloading can be minimized. If this is applied to the real system, hazard elements can be eliminated and in given time since more unloading can be done, congestion can be reduced.

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Sensitivity analysis of variable curvature friction pendulum isolator under near-fault ground motions

  • Shahbazi, Parisa;Taghikhany, Touraj
    • Smart Structures and Systems
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    • 제20권1호
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    • pp.23-33
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    • 2017
  • Variable Curvature Friction Pendulum (VCFP) bearing is one of the alternatives to control excessive induced responses of isolated structures subjected to near-fault ground motions. The curvature of sliding surface in this isolator is varying with displacement and its function is non-spherical. Selecting the most appropriate function for the sliding surface depends on the design objectives and ground motion characteristics. To date, few polynomial functions have been experimentally tested for VCFP however it needs comprehensive parametric study to find out which one provides the most effective behavior. Herein, seismic performance of the isolated structure mounted on VCFP is investigated with two different polynomial functions of the sliding surface (Order 4 and 6). By variation of the constants in these functions through changing design parameters, 120 cases of isolators are evaluated and the most proper function is explored to minimize floor acceleration and/or isolator displacement under different hazard levels. Beside representing the desire sliding surface with adaptive behavior, it was shown that the polynomial function with order 6 has least possible floor acceleration under seven near-field ground motions in different levels.

Cancer Prediction Based on Radical Basis Function Neural Network with Particle Swarm Optimization

  • Yan, Xiao-Bo;Xiong, Wei-Qing;Hu, Liang;Zhao, Kuo
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권18호
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    • pp.7775-7780
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    • 2014
  • This paper addresses cancer prediction based on radial basis function neural network optimized by particle swarm optimization. Today, cancer hazard to people is increasing, and it is often difficult to cure cancer. The occurrence of cancer can be predicted by the method of the computer so that people can take timely and effective measures to prevent the occurrence of cancer. In this paper, the occurrence of cancer is predicted by the means of Radial Basis Function Neural Network Optimized by Particle Swarm Optimization. The neural network parameters to be optimized include the weight vector between network hidden layer and output layer, and the threshold of output layer neurons. The experimental data were obtained from the Wisconsin breast cancer database. A total of 12 experiments were done by setting 12 different sets of experimental result reliability. The findings show that the method can improve the accuracy, reliability and stability of cancer prediction greatly and effectively.

비선형 내진 손상도 평가 및 보강상태함수를 이용한 기존교량의 내진 보강 전략 (Seismic Nonlinear Damage Assessment and Retrofit Strategies for Existing Bridges with Isolation System using Retrofit Slate Function)

  • 조효남;최현호;엄원석;신만규
    • 한국구조물진단유지관리공학회 논문집
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    • 제6권1호
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    • pp.179-191
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    • 2002
  • This paper presents a systematic approach to the seismic nonlinear analysis and retrofit strategies for existing bridges with isolation system using retrofit slate function newly proposed in this study. A seismic retrofit scheme using sliding base isolation system was presented to reduce the seismic hazard for bridge structures. In this study, two types of isolation systems such as lead bearings and sliding isolators were used. The behavior of sliding isolators was modeled by a triaxial interaction model. And three types of earthquakes such as El Centro, San Fernando, and the artificial were used as earthquake ground excitations. Seismic response analyses of the bridge before and after retrofit were effectively carried out by using a three-dimensional nonlinear seismic analysis program, IDARC-Bridge. Also, this paper proposes a retrofit state function for easily representing the efficiency of a retrofit scheme.

웹 기반 산불위험지수 표출시스템에서의 UML(Unified Modeling Language) 설계 사례 (Case Study of UML(Unified Modeling Language) Design for Web-based Forest Fire Hazard Index Presentation System)

  • 조윤원;조명희;안승섭
    • 한국지리정보학회지
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    • 제5권1호
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    • pp.58-68
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    • 2002
  • 최근 재해방재 사업에 대한 인식이 고조화 되면서 중앙정부나 지자체에서는 일반 국민들에게 국가에서 시행하는 재해방재 서비스를 웹이라는 공간을 통해 제공함으로서 국민들의 재해방지에 대한 관심을 부각시키려는 노력을 하고 있다. 특히, 사용자 누구든지 접근할 수 있는 웹 환경하에서 대규모의 국가적 재해로 연결될 수 있는 산불의 당일 발생위험지수를 시각화하는 서비스를 제공한다면 산불방지에 대한 국민들의 관심과 인식을 불러 일으켜 산불피해를 조금이나마 최소화하는데 도움을 줄 것이다. 본 연구에서 개발한 산불위험지수 예보시스템은 우리나라의 당일 산불위험지수를 지도상에 시각적으로 표출하고 위험지수산출에 관계되는 자료들을 텍스트 형식으로 서비스하도록 한다. 시스템 개발에 있어서는 컴포넌트를 이용하여 소프트웨어를 생산하는 방식으로 패러다임이 변해 가는 현재의 추세를 반영하기 위하여 UML(Unified Modeling Language)을 이용한 컴포넌트 기반 개발 프로세스를 설계하고 이를 통해 시스템 개발을 체계화하고자 한다. 개발된 시스템은 향후 사용자 요구 사항변경이나 서비스 영역의 확대 시 시스템 유지보수 측면에서 탄력성을 가질 것으로 예상되며 아울러 본 시스템과 유사한 서비스를 제공하는 다른 웹 GIS(Geographic Information System) 애플리케이션 개발에 있어서도 컴포넌트 재사용을 통하여 개발에 소요되는 비용과 시간을 최소화시킬 수 있을 것이라 사료된다.

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미국 위탁아동의 친권상실선고 이후 입양 결정요인에 관한 생존분석 (Timing and Risk Factors of Adoption for Legally-Free Foster Children after Having Parental Rights Terminated in the U. S.)

  • 송민경
    • 한국사회복지학
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    • 제59권1호
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    • pp.301-327
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    • 2007
  • 본 연구의 목적은 미국에서 친권상실이 선고된 위탁아동의 입양률 추이를 살펴보고, 입양결정에 영향을 미치는 주된 요인을 규명하는 데 있다. 본 연구는 미국 위탁보호와 입양에 관한 패널데이터 FY1999-FY2002를 이용하여 1998년 10월부터 2002년 9월까지 32개 주를 추출하여 총 26,895명을 분석에 활용하였다. 사건사 분석의 Kaplan-Meier 분석과 비례적 위험회귀모형(Cox proportional hazards regression model)을 이용하여 친권상실선고 이후 소요되는 위탁기간에 따른 입양률 추이와 위험 입양배율(hazard ratios for adoption)를 산출하였다. 본 연구의 주요 결과로는 친권상실선고 이후 3개월-19개월까지 입양률이 급속히 증가하다가 20개월이 지나면서 오히려 감소추세를 보이고 있었다. 입양여부와 관련한 주요 요인으로서는 백인아동일 경우, 나이가 어릴수록, 선입양가족, 도시소재의 위탁보호일 경우, 양부모 위탁가족, 또는 인종적으로 동일한 위탁부모에 의해 위탁보호 될 경우 입양가능성이 상대적으로 높게 나타났다. 또한, 아동이 지체나 장애가 있을 경우, 신체학대나 성학대를 경험한 경우, 친부모의 양육능력부족으로 위탁보호 된 경우 상대적으로 낮은 입양가능성을 보이고 있다. 본 연구결과 친권상실 이전에 발생한 위탁보호 원인이 친권상실 이후에도 입양에 영향을 미치고 있으며, 입양촉진방안으로 친권상실선고 이후 제공된 위탁서비스 활용과 적극적 지원방안 모색의 필요성이 제기되었다. 끝으로 본 연구결과를 바탕으로 한국사회에서 요보호아동의 친권개입의 정책적 방향과 항구적 보호마련을 위한 함의와 제언을 개괄적으로 제시하였다.

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Immunoregulatory Function of HLA-G in Gastric Cancer

  • Tuncel, Tolga;Karagoz, Bulent;Haholu, Aptullah;Ozgun, Alpaslan;Emirzeoglu, Levent;Bilgi, Oguz;Kandemir, Emin Gokhan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7681-7684
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    • 2013
  • Background: Human leukocyte antigen (HLA)-G-positive gastric cancers are associated with poor survival, but links with tumor escape mechanisms remain to be determined. Materials and Methods: We used immunohistochemistry to investigate HLA-G expression, tumor infiltrating CD8+ T lymphocytes, and Treg cells in 52 gastric cancer patients. Results: There were 29 cancer-related deaths during the follow-up period. Kaplan-Meier analysis indicated that patients with HLA-G-positive (n=16) primary tumors had a significantly poorer prognosis than patients with HLA-G-negative tumors (n=36, p=0.008). The median survival time was 14 months and 47 months, respectively. Patients with high numbers of Tregs and low numbers of CD8+T lymphocytes in the primary tumor had a poorer prognosis than those with low numbers of Tregs and high numbers of CD8+T lymphocytes (p=0.034, p=0.043). Multivariate Cox proportional hazard regression analysis showed that HLA-G expression (hazard ratio: 2.662; 95% confidence interval: 1.242-5.723; p=0.012) and stage (hazard ratio: 2.012;95% confidence interval: 1.112-3.715; p=0.041) were independent unfavorable factors for patient survival. Conclusions: We found a significant positive correlation between HLA-G expression and the number of tumor infiltrating Tregs (p=0.01) and a negative correlation with the number of CD8+T lymphocytes (p=0.041). HLA-G may protect gastric cancer cells from cytolysis by inducing Foxp3+Treg lymphocytes and suppressing CD8+T lymphocytes.

청년층 실업과 엄친아효과 (Youth Unemployment and the Effect of My Mom's Friend's Son)

  • 배진한
    • 노동경제논집
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    • 제33권2호
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    • pp.1-26
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    • 2010
  • 기존의 직업탐색이론을 한 단계 진전시킬 수 있는 '엄친아효과' 개념을 도입하고 그것이 청년층 미취업탈출확률에 미치는 효과를 부모님의 학력, 임시 일용직 비율, 대 중소기업 임금격차 비율 등의 대리변수들로 측정하고자 하였다. 추정 결과, 최근으로 올수록 소위 '엄친아효과'는 점차 강화되고 있다는 사실이 확인된다. 정책 함의로는 청년층의 구직기간 축소와 실업탈출 확률의 제고라는 측면에서 노동시장에서 임금이나 일자리 질의 격차가 계속 확대되는 것은 결코 바람직하지 못하며, 또한 청년층 실업문제가 단순히 노동시장 정보의 정확한 제공만으로는 쉽게 해결되기 어렵다는 점 등을 도출해 낼 수 있다.

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공공연구기관의 기술이전모형연구와 그 정책적 함의 발표분야 : 기술경제, 기술정책분야(기술이전)

  • 류태규;박종복;이정동;김태유
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 2002년도 제21회 하계학술발표회 논문집
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    • pp.203-223
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    • 2002
  • In Korea, Public Research Institutes(PRIs) are today faced with the challenges of creating values by transferring technologies in store within themselves to private commercial sector. Recently, It has been increasingly pointed out that PRIs have the poor capability to valuate prospective technologies of their own, and don't run the reasonable technology transfer mechanism in terms of establishing royalty rate and initial payment, designing remuneration to inventor, screening qualified licensee, and controlling the moral hazard. This paper develops an enhanced mathematical model of technology transfer from a PRI to a private industrial firm with including the inventor as an important player. The model is made up of the main part which derives the optimal royalty rate by maximizing the social welfare and sharing risk fairly between players and some sub-parts. The one sub-part is a principal-agent model which makes it possible to control the moral hazard of inventors, and the other part provides the criteria for screening appropriate licensees. Moreover, the moral hazard between inventor and licensee is addressed by introducing the cost reduction function of efforts exerted by them. The model is able to relate the optimal royalty rate to the parameters that represent the environments under which the concerned parties operate. Especially, the ratio of initial payment over the value of transferred technology is calculated from the binding relation with the royalty rate. The paper shows that the model suggested here is more enhanced by comparing with the existing technology transfer mechanism. Finally, the paper allows us to find better strategies for effective technology transfer and further develop more sophisticated technology transfer model.

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