• Title/Summary/Keyword: cross connection

검색결과 332건 처리시간 0.027초

사회적 환경으로서의 지원망 특성이 농촌노인의 심리적 복지에 미치는 영향 (The Effects of the Social Support Network on the Psychological Well-Being of the Rural Elderly in Korea)

  • 이정화;한경혜;박공주;이한기
    • 농촌계획
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    • 제9권3호
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    • pp.1-7
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    • 2003
  • As the proportion of the elderly population in rural area is growing rapidly, the quality of life of the rural elderly is becoming a major concern. According to Rowe and Kahn(1997), active and productive engagement in society is a central component of successful aging. Yet, the effect of various social support network on psychological well-being of the rural elderly is not well known. This study is an attempt to empirically examine the connection between social support network and psychological well-being of the rural elderly. For this purpose, community welfare specialists gathered data from 1033 rural elderly in 32 villages, using structured questionnaires. The statistical methods used for the data analysis were descriptive statistics, cross tables, ANOVA and hierarchical regression analysis using spss wins 10.0 program. The major findings of this study are as follows: The majority of rural elderly have social support networks composed of more than one person and the mean number of their social support network was ten persons. The elderly who keep frequent contact with many adult children and friend/neighbor are happier than the elderly who keep contact with fewer number of children and friends. The size of the network of relatives significantly affects the level of loneliness of the elderly. Theoretical and practical implications of this study for the improvement of the quality of life of the rural elderly is discussed.

상수관망의 맞춤형 부정류해석 및 부정류피해 최소화 방안 (Customized unsteady analysis and minimization of damage due to unsteady flow in water distribution system)

  • 권혁재;유민규
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2015년도 학술발표회
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    • pp.287-291
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    • 2015
  • 본 연구에서는 두 지역의 실제 상수관망에 대해서 부정류해석을 수행하였고 각각의 상수관망에 필요한 부정류피해 최소화방안을 제시하였다. 첫 번째 대상지역은 베트남 호치민으로 148개 절점과 162개의 파이프로 이루어진 소블럭 상수관망이며 두 번째 대상지역은 파주시 광탄면으로 512개 절점과 527개의 파이프로 이루어진 세 개의 소블럭 상수관망이다. 두지역의 상수관망은 지형적면이나 규모면에서 다른 모습을 하고 있기 때문에 부정류해석 시 발생가능한 피해유형이 틀린 것으로 나타났다. 호치민의 경우 배수지의 높이가 낮고 도시 내 표고차가 없어서 관망 내 평균수압이 $1kg/cm^2$을 약간 상회하는 수준으로 수압이 낮고 수압차 역시 작다. 따라서 상수관망에서 일어날 수 있는 소요수량의 변화나 소화전 사용과 같은 작은 변화에도 역류발생이 빈번히 일어나는 것으로 나타났으며 역류발생이 잦은 파이프를 선정할 수 있었다. 상당히 많은 파이프에서 단기간 역류가 발생하는 것을 확인할 수 있었다. 짧은 기간에 발생하는 변화에 대한 단기간 역류는 교차연결(Cross-Connection)의 문제를 야기할 수 있다. 따라서 역류발생이 빈번히 일어나는 파이프 주위에 check valve나 역지밸브등의 설치를 통해 역류로 인한 피해를 최소화할 수 있다. 파주시 광탄면 지역의 소블럭 집합으로써 고저차가 많은 지역이다. 배수지 밸브개폐 시 발생 가능한 수충격에 대한 시뮬레이션과 펌프장정지로 인해 발생할 수 있는 수충격에 발생 시뮬레이션을 수행하였고 관망내에서 자주 발생하는 밸브개폐로 인한 시뮬레이션을 수행하였다. 그 결과 광탄의 경우 수충격 발생위험 지점은 배수지 근처로 나타났고 수격압이 최대 $2.5kg/cm^2$에서 $3.0kg/cm^2$까지 발생 가능한 것으로 나타났고 밸브개폐시간이 1-2초 지연되어도 상당히 큰 수격압을 줄일 수 있는 것으로 나타났다. 수충격압이 크게 발생할 수 있는 지역에 수충격피해 최소화를 위해 surge tank와 같은 장치를 설치해야 한다. 또한 발생가능한 수격압의 크기를 통계적기법을 통해 확률밀도함수로 나타낼 수 있었다. 이 결과는 앞으로 상수관망의 설계나 운영에서 수충격피해 방지 장치 및 설비를 시공할 때 장치의 규모나 용량을 결정할 때 유용한 정보가 될 것으로 판단된다.

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철도터널 화재시 연결통로 및 대피로 제연을 위한 수치해석 연구 (Numerical Simulation of Smoke Ventilation in Rescue Route and Cross Passage of Railroad Tunnel)

  • 양성진;허남건;유홍선;김동현;장용준
    • 설비공학논문집
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    • 제20권1호
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    • pp.1-10
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    • 2008
  • A transient 3-D numerical simulation was performed to analyze the fire safety in a railway tunnel equipped with a mechanical ventilation system. The behavior of pollutants was studied for the emergency operation mode of ventilation system in case of fire in the center of the rescue station and near the escape route. Various schemes of escape route construction for connection angle($45^{\circ}$, $90^{\circ}$, 135^{\circ}$) and slope($10^{\circ}$) were evaluated for the ventilation efficiency in the fire near the escape route. From the results, it was shown that the mode of the ventilation fan operation which pressurizes the tunnel not under the fire and ventilates the smoke from the tunnel under the fire is most effective for the smoke control in the tunnel in case of the fire occurrence. It was also shown that the blowing of jet fan from the rescue tunnel to the main tunnel should be in the same direction as the flow direction in the main tunnel arising from the traffic and the buoyancy.

Progress and Prospect of Rice Biotechnology in Korea

  • Tae Young, Chung
    • 한국잠사학회:학술대회논문집
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    • 한국잠사학회 1997년도 Progress and Future Development of Sericultural Science and Technology 40th Anniversary Commemoration Symposium
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    • pp.23-49
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    • 1997
  • This is a progress report of rice biotechnology including development of gene transformation system, gene cloning and molecular mapping in rice. The scope of the research was focused on the connection between conventional breeding and biotech-researches. Plant transformation via Agrobacterium or particle bombardment was developed to introduce one or several genes to recommended rice cultivars. Two chimeric genes containing a maize ribosome inactivating protein gene (RIP) and a gerbicide resistant gene (bar) were introduced to Nipponbare, a Japonica cultivar, and transmitted to Korean cultivars. The homozygous progenies of herbicide resistant transgenic plant showed good fertility and agronomic characters. To explore the genetic resourses in rice, over 8,000 cDNA clones from immature rice seed have been isolated and sequenced. About 13% of clones were identified as enzymes related to metabolic pathway. Among them, twenty clones have high homology with genes encoding enzymes in the photorespiratory carbon cycle reaction. Up to now about 100 clones were fully sequenced and registered at EMBL and GenBank. For the mapping of quantitative tarits loci (QTL) and eternal recombinant inbred population with 164 F13 lines (MGRI) was developed from a cross between Milyang 23 and Gihobyeo, Korean rice cultivars. After construction of fully saturated RFLP and AFLP map, quantitative traits using MGRI population were analyzed and integrated into the molecular map. Eighty seven loci were determined with 27 QTL characters including yield and yield components on rice chromosomes. Map based cloning was also tried to isolate semi-dwarf (sd-1) gene in rice. A DNA probe, RG 109, the most tightly linked to sd-1 gene was used to screen from bacterial artifical chromosome (BAC) libraries and five over lapping clones presumably containing sd-1 gene were isolated. Rice genetic database including results of biotech reasearch and classical genetics is provided at Korea Rice Genome Server which is accessible with world wide web (www) browser. The server provides rice cDNA sequences and map informations linked with phenotypic images.

Numerical study on force transfer mechanism in through gusset plates of SCBFs with HSS columns & beams

  • Ebrahimi, S.;Zahrai, S.M.;Mirghaderi, S.R.
    • Steel and Composite Structures
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    • 제31권6호
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    • pp.541-558
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    • 2019
  • In Special Concentrically Braced Frames (SCBFs), vertical and horizontal components of the brace force must be resisted by column and beam, respectively but normal force component existing at the gusset plate-to-column and beam interfaces, creates out-of-plane action making distortion in column and beam faces adjacent to the gusset plate. It is a main concern in Hollow Structural Section (HSS) columns and beams where their webs and gusset plate are not in the same plane. In this paper, a new gusset plate passing through the HSS columns and beams, named as through gusset plate, is proposed to study the force transfer mechanism in such gusset plates of SCBFs compared to the case with conventional gusset plates. For this purpose, twelve SCBFs with diagonal brace and HSS columns and twelve SCBFs with chevron brace and HSS columns and beams are considered. For each frame, two cases are considered, one with through gusset plates and the other with conventional ones. Based on numerical results, using through gusset plates prevents distortion and out-of-plane deformation at HSS column and beam faces adjacent to the gusset plate helping the entire column and beam cross-sections to resist respectively vertical and horizontal components of the brace force. Moreover, its application increases energy dissipation, lateral stiffness and strength around 28%, 40% and 32%, respectively, improving connection behavior and raising the resistance of the normal force components at the gusset plate-to-HSS column and beam interfaces to approximately 4 and 3.5 times, respectively. Finally, using such through gusset plates leads to better structural performance particularly for HSS columns and beams with larger width-to-thickness ratio elements.

Analytical, experimental and numerical study of timber-concrete composite beams for bridges

  • Molina, Julio C.;Calil, Carlito Junior;de Oliveira, Diego R.;Gomes, Nadia B.
    • Computers and Concrete
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    • 제24권2호
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    • pp.103-115
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    • 2019
  • In this study, the strength and stiffness (EI) of wood-concrete composite beams for bridges with T-shaped cross section were evaluated. Two types of connectors were used: connectors bonded with epoxy adhesive and connectors attached to the wood just by pre-drilling (without adhesive). The connectors consisted of common steel bars with a diameter of 12.5 mm. Initially, the strength and stiffness (EI) of the beams were analyzed by bending tests with the load applied at the third point of the beam. Subsequently, the composite beams were evaluated by numerical simulation using ANSYS software with focus on the connection system. To make the composite beams, Eucalyptus citriodora wood and medium strength concrete were used. The slip modulus K and the ultimate strength values of each type of connector were obtained by direct shear tests performed on composite specimens. The results showed that the connector glued with epoxy adhesive resulted in better strength and stiffness (EI) for the composite beams when compared to the connector fixed by pre-drilling. The differences observed were up to 10%. The strength and stiffness (EI) values obtained analytically by $M{\ddot{o}}hler^{\prime}$ model were lower than the values obtained experimentally from the bending tests, and the differences were up to 25%. The numerical simulations allowed, with reasonable approximation, the evaluation of stress distributions in the composite beams tested experimentally.

집단창의성 발현을 위한 모바일, 온/오프라인 연계 수학 학습 콘텐츠 개발 (Development of mobile, online/offline-linked math learning content to promote group creativity)

  • 김부미
    • 한국학교수학회논문집
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    • 제25권1호
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    • pp.39-60
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    • 2022
  • 본 연구에서는 고등학생의 집단창의성 발현을 돕기 위해 범교과 학습주제인 '환경'과 연계하여 관련 문제를 다항함수로 표현하고 제한된 범위에서 함수의 최댓값과 최솟값을 구하는 모바일, 온/오프라인 연계 수학 학습 콘텐츠를 개발하고자 한다. 이를 위해 학교수학에서의 집단창의성 개념과 발현과정, 집단창의성 발현과정 요소와 모바일, 온/오프라인 구현 기능을 탐색하였다. 이를 바탕으로 모바일, 온/오프라인 연계 협력 학습을 통해 집단창의성을 발현할 수 있는 하이브리드 앱 '지구를 생각하는 Best Box 제작'과 학습관리시스템(LMS)을 개발하였다. 모바일, 온/오프라인을 연계한 수학 학습이 효율적으로 운영될 수 있도록 교수학습지도안도 함께 개발하였다. 예비연구 결과, 하이브리드 앱 '지구를 생각하는 Best Box 제작'은 상호보완적-메타인지적 상호작용을 기반으로 집단유창성과 집단정교성을 구현하기에 적합한 것으로 나타났다.

Veterinarians as a Risk Group for Zoonoses: Exposure, Knowledge and Protective Practices in Finland

  • Kinnunen, Paula M.;Matomaki, Alisa;Verkola, Marie;Heikinheimo, Annamari;Vapalahti, Olli;Kallio-kokko, Hannimari;Virtala, Anna-Maija;Jokelainen, Pikka
    • Safety and Health at Work
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    • 제13권1호
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    • pp.78-85
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    • 2022
  • Background: Veterinarians may encounter a variety of zoonotic pathogens in their work. Methods: We conducted two cross-sectional questionnaire studies among veterinarians in Finland. Participants were recruited during two Annual Veterinary Congresses. In 2009, 306 veterinarians participated in an extensive questionnaire study, and in 2016, 262 veterinarians participated in a more focused study that included two same questions. Results: In 2009, the majority (90.9%) of the participating veterinarians reported having been occupationally exposed to zoonotic pathogens. Zoonotic infections (15.0%), needle stick incidents (78.8%), bites (85.0%), as well as infected skin lesions (24.2%) were reported. In 2009, 8.2% of the participants fully agreed with the statement "I have good knowledge of zoonoses and their prevention"; in 2016, the proportion was 10.3%. The reported use of protective practices and personal protective equipment in connection with specific veterinary procedures indicated that there was room for improvement, particularly in protection from pathogens that are transmissible via inhalation and mucous membranes. Conclusion: The results confirm that veterinarians are commonly occupationally exposed to zoonotic pathogens. Education should aim to improve and maintain the knowledge of zoonoses and their prevention. Use of protective practices should be advocated.

치매안심센터 간호사의 업무 중요도와 수행도에 대한 연구 (A Study on the Work Importance and Work Performance of Nurses in the Dementia Relief Center)

  • 장현정;마예원;박혜선;임선영
    • 대한통합의학회지
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    • 제10권2호
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    • pp.187-202
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    • 2022
  • Purpose : This study is a descriptive research study to establish basic data for stable operation of dementia relief center as a part of national responsibility system for dementia and to establish the role of the professional workforce. Methods : This study is a survey study involving 126 nurses working at 19 dementia relief centers. The collected data were analyzed using the SPSS/WIN 23.0. Results : The importance tasks that nurses think of were Dementia Diagnosis, Counseling, Register and Classification and Dementia Preventive Projects. In addition, tasks that showed high performance were in the order of Dementia Diagnosis, Counseling, Register and Classification, Management of Dementia subjects. As a result, the final items of work areas and contents included 45 subcategories of work content for eight work areas. Conclusion : Through this study, it was possible to investigate the overall work area and content of nurses at the Dementia relief Center. It is necessary to develop a work description suitable for nurses who are medical personnel specializing in dementia safety centers. It is necessary to develop a work description suitable for nurses who are medical personnel specializing in dementia safety centers. In connection with the purpose of establishing the centers for disease control and prevention, it is necessary to operate a systematic and continuous program to manage dementia patients and those with mild cognitive impairment in the community.

Pseudo-BIPV Style Rooftop-Solar-Plant Implementation for Small Warehouse Case

  • Cha, Jaesang;Cho, Ju Phil
    • International journal of advanced smart convergence
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    • 제11권3호
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    • pp.187-196
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    • 2022
  • In this paper, we propose an example of designing and constructing a roof-type solar power plant structure equipped with a Pseudo-BIPV (Building-Integrated Photovoltaic) shape suitable for use as a roof of a small warehouse with a sandwich-type panel structure. As the characteristics of the roof-type solar power generation facility to be installed in the small warehouse proposed in this study, the shape of the roof is not a general A type, but a right-angled triangle shape with the slope is designed to face south. We chose a structure in which an inverter for one power plant and a control facility are linked by grouping several roofs of buildings. In addition, the height of the roof structure is less than 20 cm from the floor, and it has a shape similar to that of the BIPV, so it is building-friendly because it is almost in close contact with the roof. At the same time, the roof creates a reflective light source due to the white color. By linking this roof with a double-sided solar panel, we designed it to obtain both the advantage of the roof-friendliness and the advantage of efficiency improvement for the electric power generation based on the double-sided panel. Compared to the existing solar power generation facilities using A-shaped cross-sectional modules, the power generation efficiency of roofs in this case is increased by more than 11%, which we can confirm, through the comparison analysis of monitoring data between power plants in the same area. Therefore, if the roof-type solar structure suitable for the small warehouse we have presented in this paper is used, the facilities of electric power generation is eco-friendly. Further it is easier to obtain facility certification compared to the BIPV, and improved capacity of the power generation can be secured at low material cost. It is believed that the roof-type solar power generation facility we proposed can be usefully used for warehouse or factory-based smart housing. Sensor devices for monitoring, CCTV monitoring, or safety and environment management, operating in connection with the solar power generation facilities, are linked with the Internet of Things (IoT) solution, so they can be monitored and controlled remotely.