• 제목/요약/키워드: population phenomena

검색결과 141건 처리시간 0.029초

우리나라 주변 해양생태계의 장기 변동 (Long Term Changes Pattern in Marine Ecosystem of Korean Waters)

  • ;이충일
    • 해양환경안전학회지
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    • 제18권3호
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    • pp.193-198
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    • 2012
  • 겨울철 해표면 수온 및 한국 주변역 생태계의 장기 변화 특성 및 상관관계를 분석하였다. 기후 및 해양환경의 변화와 동반된 어획강도의 변화는 1970 년대 이후 어획량 증가의 주요 원인으로 나타났다. 한국 주변역의 겨울철 SST는 1980년대 후반 기후체제변환 시점을 중심으로 상대적으로 저수온에서 고수온으로 변화되었다. 평균영양단계(MTL)는 1970년대 중반 이후 지속적으로 감소하기 시작하였으며, 하위영양단계 어류의 어획량 증가가 중요 변수로 작용하였다. 통합생태계 기반 자원평가 방법중 한가지인 FIB 지수는 1970년 초부터 1970년 후반까지 증가하였으며, 이후 일정 수준을 유지하였다. 특히, 중간영양단계에 위치하는 멸치와 정어리의 개체수 변화는 1970년대 초 이후 MTL 변화의 주요 인자로 작용하였다.

서울시의 소방서 최적입지에 관한 연구 (The Study for the Optimal Location of Fire Stations in Seoul)

  • 김근영;강성일
    • 한국방재학회 논문집
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    • 제2권1호
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    • pp.153-159
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    • 2002
  • 재해는 인간의 생명과 재산을 안전하게 보호하기 위해서 발생을 사전에 예방하고, 불가피하게 발생하였을 경우 그 경제적, 사회적, 정신적 손해를 최소화하여야 하는 모든 현상을 의미한다. 본 연구는 인위재해중 교통사고 다음으로 발생빈도가 높은 화재를 연구의 대상으로, 서울시를 연구대상지역으로 하여 서울시 주민들이 가장 최적의 소방서비스를 받을 수 있는 소방서 입지를 분석하였다. 연구의 방법으로는 최적화분석기법의 일종인 "최대수용입지문제"를 주요 연구방법으로 적용하였으며 지리정보시스템을 적용하여 현행 소방서와 화재발생의 입지적 분포를 관찰하였다. 연구의 결과로 현행 서울시 소방서 및 소방파출소의 입지는 개선의 여지가 있으며 보다 신속한 소방서비스를 받기 위해 소방차 출동지역에 대한 일부 조정이 필요할 것으로 분석되었다.

A Study on Factors Affecting Work Ability in Korean Workers

  • Lee, Yujeong;Chang, Seong Rok
    • 대한인간공학회지
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    • 제34권4호
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    • pp.327-334
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    • 2015
  • Objective: The purpose of this study was to evaluate Korean workers' work ability and to identify its contributing factors. Background: In order for Korea to overcome the phenomena of becoming an aged society, older adults must participate in the workforce to balance out the population; workers' work ability must also be maintained. In addition, influential factors in employees' capabilities and degrees of importance thereof should be identified in advance to maintain work ability. Method: The Work Ability Index (WAI) questionnaire was completed by 5,708 Korean workers. Survey questionnaire consisted items of current work ability, physical and mental demands of the job, numbers of diseases, work impairment due to diseases, sick leaves, work ability in 2 years and mental resources. Results: Results indicated that work ability and length of service increased with age. It was also found that employees in administrative positions had greater work ability than site workers, workers directly managed by a supervisor had greater work ability than workers in cooperative firms, and workers who performed intellectual tasks had greater work ability than workers who performed physical labor. Job stress was additionally observed to contribute towards overall work ability. And musculoskeletal disorders (MSDs) were found to negatively affect work ability. Conclusion: The strongest determining factors in the work ability of Korean workers were stress level and mental state. Therefore, when the WAI is used to assess Korean workers, the weighting of WAI items pertaining to physical and mental abilities should be adjusted accordingly to account for these factors. Application: The result is expected to suggest that workers maintain work ability in an aged society.

토지정보체계를 활용한 토지이용분석에 관한 연구 (A Study on Urban Land Use Analysis using Land Information Systems)

  • 이우종
    • Spatial Information Research
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    • 제2권2호
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    • pp.117-134
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    • 1994
  • 도시토지이용의 문제는 인구와 시설이 증가함에 따라 점점더 심각해지고 있으며 토지이용계획은 도시계획에서 가장 중요한 부분이다. 따라서 도시토지이용의 현상을 파악하고 미래를 예측하는 것은 토지이용계획의 핵심적인 과정이라 할 수 있다. 토지위에서 일어나는 제 현상들을 이해하기 위해서는 정확한 토지정보를 확보하는 것이 중요하며 토지이용의 효율적인 관리를 위해서는 종합적인 토지정보체계를 구축하는 것이 필요하다. 본 연구에서는 도시의 토지이용분석을 위한 기본적 단계로서 토지정보체계의 기능, 목표, 구성, 활용방안등을 고찰하고 데이타베이스를 작성하는데 필요한 자료선정과 입력사항을 국내외 한가지 사례와 일본의 사례를 통하여 분석함으로써 토지이용분석을 위한 토지정보체계의 구축방안을 모색하였다. 이러한 연구를 통하여 토지이용의 시계열적 변화패턴을 파악하고 그 요인을 분석함과 동시에 장래의 변화가 예측되는 토지이용계획을 수립함으로써 바람직한 토지이용을 유도하고 조정가능한 방안을 강구할 수 있을 것으로 사료된다.

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Crystal Structure and Tautomerism Study of the Mono-protonated Metformin Salt

  • Wei, Xiaodan;Fan, Yuhua;Bi, Caifeng;Yan, Xingchen;Zhang, Xia;Li, Xin
    • Bulletin of the Korean Chemical Society
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    • 제35권12호
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    • pp.3495-3501
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    • 2014
  • A novel crystal, the mono-protonated metformin acetate (1), was obtained and characterized by elemental analysis, IR spectroscopy and X-ray crystallography. It was found that one of the imino group in the metformin cation was protonated along with the proton transfer from the secondary amino group to the other imino group. Its crystal structure was then compared with the previously reported diprotonated metformin oxalate (2). The difference between them is that the mono-protonated metformin cations can be linked by hydrogen bonding to form dimers while the diprotonated metformin cations cannot. Both of them are stabilized by intermolecular hydrogen bonds to assemble a 3-D supermolecular structure. The four potential tautomer of the mono-protonated metformin cation (tautomers 1a, 1b, 1c and 1d) were optimized and their single point energies were calculated by Density Functional Theory (DFT) B3LYP method based on the Polarized Continuum Model (PCM) in water, which shows that the most likely existed tautomer in human cells is the same in the crystal structure. Based on the optimized structure, their Wiberg bond orders, Natural Population Analysis (NPA) atomic charges, molecular electrostatic potential (MEP) maps were calculated to analyze their electronic structures, which were then compared with the corresponding values of the diprotonated metformin cation (cation 2) and the neutral metformin (compound 3). Finally, the possible tautomeric mechanism of the mono-protonated metformin cation was discussed based on the observed phenomena.

범죄예방 및 안전사고 감소를 위한 CCTV시스템의 활용방안에 관한 연구 (Research on Utilizing Method of CCTV System for Crime Prevention and Safety Accident Reduction)

  • 김태환
    • 한국재난정보학회 논문집
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    • 제3권1호
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    • pp.55-68
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    • 2007
  • Recently, people in cities of developed countries are exposed to unfortified damages of crime and disaster due to urbanization, industrialization and information-oriented era caused by congestion of population in terms of hardware and various social pathology phenomena and frequent and large scale of disaster caused by crime and disorder, which occur in the course of going through nuclear family, a gap between rich and poor and aging society in terms of software. In this regard, demand for security upon individual life and property has been increased but the police that are responsible for the public security does not effectively reduce damage in life and property because their activities are mainly oriented in coping with security accidents more than prevention. Shortage of manpower and budget, retarded equipment, and heavy overwork are the reasons. In order to confront with this kind of situation, we should utilize CCTV system with the purpose of declining possible chances of crime, not for eliminating cause of crime as crime prevention activities to predict danger in advance as a way of prevention and we may expect a role of damage prevention by installing CCTV in places where security accident may possibly happen. In conclusion, there are invasion of privacy, misuse of the system, insufficiency of overall monitoring office management, lack of citizens' understanding and economical allotment of the system installation costs in installation of CCTV system. However. it is necessary to install the CCTV system for effective prevention of crime and prevention activities of security accidents and accurate PR of purposes of installing CCTV to local residents, establishing relevant laws about system misuse, allotment of equipment costs and fees by R&D of the system machinery, cost reduction method of storage, management and replacement, saving costs from co-operative attitude of government, and local autonomous entities and local residents should be involved.

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$Pr^{3+}$이 도핑된 광섬유증폭기의 최적화 및 과도현상에 관한 연구 (A Study on the Optimization and the Transient Phenomena of the $Pr^{3+}$ doped Fiber Amplifier)

  • 이재명;지명훈;염진용;이영우
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2001년도 춘계종합학술대회
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    • pp.333-336
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    • 2001
  • 본 논문에서는 1.3$\mu\textrm{m}$ 대역에서 증폭특성을 갖는 PDFA의 과도응답 특성을 이론적으로 해석하였다. 수치모델은 밀도반전의 형성과정, 여기파워, 신호파워와 증폭기를 따라 변화하는 신호파워를 포함하고 광섬유 증폭기의 길이에 따른 각 에너지준위의 밀도, 여기파워, 이득의 해서과 시간의 변화에 따른 각 에너지준위의 밀도변화와 이득을 해석하였다. 이러한 수치해석의 결과는 광섬유증폭기의 이득 포화와 복구시간을 예측할 수 있게 해주고, 이득의 포화와 복각시간이 광 펄스의 증폭에 미치는 영향을 예측한 수 있게 한다. 시뮬레이션의 결과, 여기광의 파장 1.017$\mu\textrm{m}$, 파워 0.5W이고 광섬유증폭기의 Pr 이온의 도핑농도가 1000ppm일 경우 광섬유증폭기의 길이 약 5m 에서 이득의 포화가 이루어 졌으며 30dB의 이득을 얻었다. 또한 상준위의 이온밀도는 약 250$\mu\textrm{s}$의 시간이 지난후에 포화됨을 알 수 있었다.

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소형주택의 실내코디네이션 평가요소 분석에 관한 연구 - 한국과 일본의 85㎡이하 소형주택을 중심으로 - (A Study on Evaluation Elements for Interior Coordination of Small-sized Housing - Focused on the below ㎡ small-sized housing between Korea and Japan -)

  • 김소희;서민우;한영호
    • 한국실내디자인학회논문집
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    • 제22권1호
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    • pp.194-202
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    • 2013
  • In the modern society, phenomena such as a decrease in population and an increase in urban small houses caused by demographic changes, a decrease in midium-large housing constructions, and the concentration of one to two person families in the capital area cultivated ground for the growth of small house market. In response to these trends, interior coordination becomes a critical factor to be applied to the small houses in order to suit the residents' needs in most convenient, efficient and aesthetic ways. Therefore, an evaluation element is in demand to extract, evaluate and constantly improve the interior coordination elements. This study extracts and analyzes the essential elements required for small houses into spatial structure, system coordination and interior coordination. In domestic cases, most of spatial structure was conventional and linear while in foreign countries, various variations were found to reflect the needs from different consumers. For the system coordination, convenience played the most important role to emphasize on the easy use of digital system and built-in appliance system in domestic cases. However, in foreign countries, safety issue and economic aspects were the most considered when it comes to the interior coordination. In regard to interior coordination, installations of the storages for the limited small spaces that also support as extended spaces were rare to find in both cases for domestic and international settings. It is expected that systematic studies focused on more objective standards for interior coordination shall be implemented to provide indicators to measure the interior coordination cases in the near future.

Effect of cold stress on infanticide by female Swiss albino mice Mus musculus: a pilot study

  • Zafar, Tabassum;Naik, Ab Qayoom;Shrivastava, Vinoy K.
    • Journal of Animal Science and Technology
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    • 제60권4호
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    • pp.7.1-7.5
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    • 2018
  • Background: Mice are widely accepted research models of great clinical significance. Maintenance of laboratory mice breed is an essential aspect for performing research activities in various fields of science. Infanticide is one of the prominent causes of litter loss during maintenance of laboratory mice stock. The present study is an effort to monitor the effect of change in ambient temperature of female mice below the normal range on cannibalism and infanticide during early postparturition phase. Adult female Swiss albino mice have been divided into two groups of control and treatment. On the day of litter group one was maintained under controlled temperature conditions (minimum $20^{\circ}C$ to maximum $23^{\circ}C$) throughout, while female mice belong to group two have been exposed to variation of room temperature (maximum $15^{\circ}C$ to minimum $10^{\circ}C$ for two nights and one day) until 36 h postparturition. Results: The effects of temperature changes were observed on the infanticide behaviour of dams along with the survival of pups in early postparturition phase till 36 h after delivery. The significant statistical difference (P < 0.05) was reported in infanticide behaviour of dams when control and treatment group was compared. It is observed that decrement in surrounding temperature promotes decrement in the ambient body temperature of dams during early postparturition. It is proposed that alteration of hypothalamic homeostasis due to temperature change induces cannibalism and infanticide behaviour. Lack of thermoregulation during early postparturition creates the sense of insecurity, in-satiety, anxiety and stress. Conclusions: Authors strongly recommend the maintenance of body and surrounding temperature to prevent infanticidal behaviour and cannibalism within Swiss albino mice population. Further investigations are advisable to authenticate the active behavioural and biochemical pathway behind the phenomena.

원자로시설의 경년열화 종합관리에 관한 규정개발 방향 (Development of Regulation on the Integrated Materials Aging Management for Nuclear Facilities)

  • 신호상;홍진기;김진수;정연기;정명조;정해동;최영환
    • 한국압력기기공학회 논문집
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    • 제7권4호
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    • pp.12-18
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    • 2011
  • The renewed global interest in nuclear power has arisen from the need to reduce greenhouse gas emissions and to provide sufficient electricity for a growing global population. Many countries with nuclear power plants (NPPs) are still implementing license extensions of 10~20 years, and even consideration is being given to the concept of life-beyond-60, a further period of license extension from 60 to 80 years. To solve the materials aging problem is integral to its success. A foundation for effective aging management of nuclear power plants is that aging is properly taken into account at each stage of a plant's lifetime, i.e. in design, manufacture, construction and operation including long term operation and decommissioning. To evaluate the plant aging phenomena, a lot of background information such as materials and environment of the parts of the reactor and plant systems is needed by the experts. Information on degradation mechanisms is also used. In this paper, a regulation on the integrated materials aging management for nuclear facilities is proposed. The proposed regulation identifies key elements of effective aging management for nuclear power plants and provides the requirements on aging management for nuclear facilities throughout all stages of the lifetime of the plant.