• 제목/요약/키워드: power balance control

검색결과 325건 처리시간 0.024초

온실 스크린의 장파복사 방사율 및 흡수율 결정 (Determination of Thermal Radiation Emissivity and Absorptivity of Thermal Screens for Greenhouse)

  • 라피크아딜;나욱호;라쉬드아드난;김현태;이현우
    • 생물환경조절학회지
    • /
    • 제28권4호
    • /
    • pp.311-321
    • /
    • 2019
  • 온실에서 겨울철 야간에는 열손실을 줄이기 위한 목적으로, 여름철 주간에는 차광을 위한 목적으로 스크린을 사용하고 있다. 온실의 냉난방 에너지 절감효과에 큰 영향을 미치는 스크린의 장파복사 방사율과 흡수율은 온실에 설치할 적절한 스크린을 선택하는데 있어서 중요한 요소가 되며 이러한 특성값들을 정확하게 측정할 수 있는 방법이 필요하다. 외부 환경조건에서 스크린의 장파복사 특성의 측정과 관련된 연구가 일부 수행된 바 있지만 모든 종류의 스크린에 적용할 수 있는 방법은 아니고 공극이 있는 스크린 자재에만 적용이 가능한 방법이다. 본 연구에서는 순복사계 및 야간복사계를 사용하여 온실 스크린의 장파복사 흡수량과 방사량을 측정하고, 방사율, 흡수율 및 투과율을 결정하는 새로운 방법을 제시하였다. 특성값의 측정은 공극이 0인 4가지 종류의 스크린 자재에 대하여 수행하였다. 모든 자재가 장파복사 방사량이 흡수량보다 높게 나타났다. PE, LD-13, LD-15 and PH-2의 장파복사 방사율은 각각 $0.439{\pm}0.020$, $0.460{\pm}0.010$, $0.454{\pm}0.004$, and $0.499{\pm}0.006$ 범위로 나타났다.

국제프랜차이징 연구요소 및 연구방향 (Research Framework for International Franchising)

  • 김주영;임영균;심재덕
    • 마케팅과학연구
    • /
    • 제18권4호
    • /
    • pp.61-118
    • /
    • 2008
  • 본 연구는 국내외 프랜차이즈의 해외진출에 대한 연구들을 바탕으로 국제프랜차이징연구의 전체적인 연구체계를 세워보고, 연구체계를 형성하고 있는 연구요인들을 확인하여 각 연구요소별로 이루어지는 연구주제와 내용을 살펴보고, 앞으로의 연구주제들을 제안하고자 한다. 주요한 연구요소들은 국제프랜차이징의 동기 및 환경 요소과 진출의사결정, 국제프랜차이징의 진입양식 및 발전전략, 국제프랜차이징의 운영전략 및 국제프랜차이징의 성과이다. 이외에도 국제프랜차이징 연구에 적용할 수 있는 대리인이론, 자원기반이론, 거래비용이론, 조직학습이론 및 해외진출이론들을 설명하였다. 또한 국제프랜차이징연구에서 보다 중점적으로 개발해야 할 질적, 양적 방법론을 소개하였으며, 마지막으로 국내연구의 동향을 정리하여 추후의 연구방향을 종합적으로 정리하였다.

  • PDF

최대 수명을 갖는 AODV 라우팅 프로토콜 실험 설계 (Experimental Design of AODV Routing Protocol with Maximum Life Time)

  • 김용길;문경일
    • 한국인터넷방송통신학회논문지
    • /
    • 제17권3호
    • /
    • pp.29-45
    • /
    • 2017
  • 애드 혹 센서 네트워크는 분산형 구조와 구축으로 특징지어지며 센서 네트워크는 낮은 이동성과 엄격한 에너지 요구 조건 등을 제외하고는 애드 혹 네트워크의 기본적인 특징을 모두 갖추고 있다. 기존 프로토콜은 내결함성, 분산 컴퓨팅, 견고성, 확장성 및 신뢰성과 같은 특성 간에 서로 다른 보완성을 제공한다. 지금까지 제안된 무선 프로토콜은 매우 제한되어있어 일반적으로 단일 기지국 또는 센서 데이터 수집에 중점을 두었다. 그러한 제약을 가지는 주된 이유는 네트워크 활동을 유지하기 위해 최대 수명을 유지하기 때문에 네트워크 수명은 애드 혹 네트워크에서 중요한 설계 기준이며 모든 노드가 라우터 역할을 수행하여 에너지 부족인한 일부 노드가 동작하지 않으면 다른 노드로 통신할 수 없다. 본 논문에서는 네트워크 노드의 에너지 통신을 최적화하기 위한 실험적인 애드 혹 주문형 거리 벡터 라우팅 프로토콜을 제안 한다 부하 분산은 경로 선택 단계에서 소진된 노드의 선택을 피하고 노드 간 에너지 사용의 균형을 유지하고 네트워크 수명을 극대화한다. 전송 제어 단계에서는 신호 전송 범위를 증가시키는 높은 전송 전력의 선택과 홉 수를 줄이고 네트워크 연결 비용의 부담을 줄이는 낮은 전력 수준 사이의 균형이 필요하다.

노인을 대상으로 한 율동 운동 프로그램 실시 효과: 낙상 위험 요인과 관련하여 (Effect of Rhythmic Exercise Program to Elderly on Risk Factors of Fall Injury)

  • 이인숙;진영란;이동욱;김윤아;백경애
    • 지역사회간호학회지
    • /
    • 제12권3호
    • /
    • pp.600-608
    • /
    • 2001
  • Accidents are the fourth-leading causal factor of death among the elderly, and fall is a major type of accident (53.17%). Many cases of falls in the elderly result in delayed discovery and loss of quality of life. As the number of the elderly grows, falls will be a more important health problem. Most previous research on falls investigated prevalence. mortality, and the related factors. There are many studies proving the effect of rhythmic movements. But few researches considered linking risk factors of fall with rhythmic movements. Purpose: We want to show the changes after performing rhythmic movement program, in risk factors of falls and mobility such as flexibility, balance, muscle power and persistency in the elderly, in order to provide basic information needed for the development of fall injury prevention program for the elderly. Method: The design of this study is quasi-experimental, the equivalent control group, pretest-posttest. The subjects consist of 124 people who lived in Do-Bong-Qu. Seoul, agreed to participate in this study, and were able to follow this rhythmic movement program. About 93 % of them are from 65 to 84 years (Mean${\pm}$sd: $73.7{\pm}5.7$): 64% are female. The rhythmic movement program was designed. and performed by two community health nurses working in the Do-Bong-Gu Public Health Center, regularly twice a week from May, 4 to December, 17. in 10 senior citizens' community centers. Risk factors of fall were measured with RAFS- II (Risk Assessment for Falls Scale II) by asking about each item: mobility was measured by observing their specific movements asked by investigators. Results: 1. After performing the program during 7 months, risk factors score of falls were decreased significantly (paired-t = 4.77. p<0.01). 2. After performing the program during 7 months, flexibility (paired-t = 2.26. p=0.03) and mobility were improved (paired-t = 4.98. p<0.01). but muscle power and persistency did not change (paired-t = 0.33. p=0.74). Overall, mobility affecting the occurrence of falls was improved significantly (paired-t = 5.15. p<0.01). Conclusions: A regular rhythmic movement program can be helpful in preventing falls in the elderly. Further. we can develop a fall injury prevention program using rhythmic movement.

  • PDF

복합에너지시스템의 성능개선에 관한 연구 (A Study on System Retrofit of Complex Energy System)

  • 최정훈;문채주;장영학
    • 한국전자통신학회논문지
    • /
    • 제16권1호
    • /
    • pp.61-68
    • /
    • 2021
  • 풍력이나 태양광 같은 재생에너지의 활용은 온실가스 감축과 경제성 확보를 얻기 위해서 많은 나라에서 피할 수 없는 선택이 되고 있다. 그러나 재생에너지의 간헐성 때문에 계통으로 연계되는 재생에너지의 비중이 커지게 되어 얻어지는 문제가 더욱 크게 부각되고 있다. 복합에너지시스템은 일반적으로 2개 이상의 재생에너지원이 서로 함께 사용되면서 시스템 효율을 증가시킬 뿐만 아니라 에너지 공급에서 더욱 안정적이다. 전력시스템을 비교해 보면 복합에너지시스템의 제어 및 최적화는 모델링, 운전 및 운영계획의 요소가 더욱 어려워진다. 마이크로그리드시스템을 갖는 삼마도에 대한 복합에너지시스템 성능개선의 주 목적은 다양한 분산전원, 에너지저장장치, 전력계통의 신뢰성을 확보하기 위해서 상호 조화롭게 조정하는 것으로 운전비용을 줄이고 최상의 경제적인 이득을 얻기 위한 것이다. 본 논문은 최적의 마이크로그리드시스템을 갖는 개선된 삼마도 복합에너지시스템을 제안한다. 시험운전결과 ESS의 SOC 변동폭이 약 12%로 낮아졌으며, 태양광 발전제약이 제거되었고, 디젤발전기의 운전시간이 감소함을 확인할 수 있었다.

한국형 동반성장 정책의 방향과 과제 (The Policy of Win-Win Growth between Large and Small Enterprises : A South Korean Model)

  • 이장우
    • 중소기업연구
    • /
    • 제33권4호
    • /
    • pp.77-93
    • /
    • 2011
  • 본 연구는 최근 사회경제적 이슈가 되고 있는 동반성장의 개념과 실천 방향에 대해 논의하고자 한다. 이를 위해 동반성장의 정책적 개념을 살펴보고 유사한 개념인 상생협력과 공생발전과도 비교 분석하고자 한다. 또한 동반성장을 통해 글로벌 경쟁력을 만들어 낸 선진국 사례들로부터 교훈을 찾아내고 우리의 사회 문화적 특성에 맞는 한국형 모델을 제안하고자 한다. 한국형 동반성장 모델은 미국의 시장중심형, 일본의 문화기반형, 유럽의 정책주도형 등의 장점을 융합할 필요가 있다. 이를 위해 한국형 모델은 공동체적 에너지를 창출해내는 한국인의 잠재력 활용, 통제와 자율의 융합형 제도 개선, 미래지향적 협력관계를 위한 기업들의 행동변화 등 세 가지 요인을 핵심으로 할 필요가 있다. 한국형 모델의 실현을 위해 필요한 정부의 역할과 과제, 그리고 동반성장위원회의 역할에 대해서도 논의하고자 한다.

한국의 지역개발과 댐건설 (Regional Development And Dam Construction in Korea)

  • 안경모
    • 물과 미래
    • /
    • 제9권1호
    • /
    • pp.38-42
    • /
    • 1976
  • Because of differences in thoughts and ideology, our country, Korea has been deprived of national unity for some thirty years of time and tide. To achieve peaceful unification, the cultivation of national strength is of paramount importance. This national strength is also essential if Korea is to take rightful place in the international societies and to have the confidence of these societies. However, national strength can never be achieved in a short time. The fundamental elements in economic development that are directly conducive to the cultivation of national strength can be said to lie in -a stable political system, -exertion of powerful leadership, -cultivation of a spirit of diligence, self-help and cooperation, -modernization of human brain power, and -establishment of a scientific and well planned economic policy and strong enforcement of this policy. Our country, Korea, has attained brilliant economic development in the past 15 years under the strong leadership of president Park Chung Hee. However, there are still many problems to be solved. A few of them are: -housing and home problems, -increasing demand for employment, -increasing demand for staple food and -the need to improve international balance of payment. Solution of the above mentioned problems requires step by step scientific development of each sector and region of our contry. As a spearhead project in regional development, the Saemaul Campaign or new village movement can be cited. The campaign is now spreading throughout the country like a grass fire. However, such campaigns need considerable encouragement and support and the means for the desired development must be provided if the regional and sectoral development program is to sucdceed. The construction of large multipurpose dams in major river basin plays significant role in all aspects of national, regional and sectoral development. It ensures that the water resource, for which there is no substitute, is retained and utilized for irrigation of agricultural areas, production of power for industry, provision of water for domestic and industrial uses and control of river water. Water is the very essence of life and we must conserve and utilize what we have for the betterment of our peoples and their heir. The regional and social impact of construction of a large dam is enormous. It is intended to, and does, dras tically improve the "without-project" socio-economic conditions. A good example of this is the Soyanggang multipurpose dam. This project will significantly contribute to our national strength by utilizing the stored water for the benefit of human life and relief of flood and drought damages. Annual average precipitation in Korea is 1160mm, a comparatively abundant amount. The catchment areas of the Han River, Keum River, and Youngsan River are $62,755\textrm{km}^2$, accounting for 64% of the national total. Approximately 62% of the national population inhabits in this area, and 67% of the national gross product comes from the area. The annual population growth rate of the country is currently estimated at 1.7%, and every year the population growth in urban area increases at a rising rate. The population of Seoul, Pusan, and Taegu, the three major cities in Korea, is equal to one third of our national total. According to the census conducted on October 1, 1975, the population in the urban areas has increased by 384,000, whereas that in rural areas has decreased by 59,000,000 in the past five years. The composition of population between urban and rural areas varied from 41%~59% in 1959 to 48%~52% in 1975. To mitigate this treand towards concentration of population in urban areas, employment opportunities must be provided in regional and rural areas. However, heavy and chemical industries, which mitigate production and employment problems at the same time, must have abundant water and energy. Also increase in staple food production cannot be attained without water. At this point in time, when water demand is rapidly growing, it is essential for the country to provide as much a reservoir capacity as possible to capture the monsoon rainfall, which concentarated in the rainy seaon from June to Septesmber, and conserve the water for year round use. The floods, which at one time we called "the devil" have now become a source of immense benefit to Korea. Let me explain the topographic condition in Korea. In northern and eastern areas we have high mountains and rugged country. Our rivers originate in these mountains and flow in a general southerly or westerly direction throught ancient plains. These plains were formed by progressive deposition of sediments from the mountains and provide our country with large areas of fertile land, emminently suited to settlement and irrigated agricultural development. It is, therefore, quite natural that these areas should become the polar point for our regional development program. Hower, we are fortunate in that we have an additional area or areas, which can be used for agricultural production and settlement of our peoples, particularly those peoples who may be displaced by the formation of our reservoirs. I am speaking of the tidelands along the western and southern coasts. The other day the Ministry of Agriculture and Fishery informed the public of a tideland reclamation of which 400,000 hectares will be used for growing rice as part of our national food self-sufficiency programme. Now, again, we arrive at the need for water, as without it we cannot realize this ambitious programme. And again we need those dams to provide it. As I mentioned before, dams not only provide us with essential water for agriculture, domestic and industrial use, but provide us with electrical energy, as it is generally extremely economical to use the water being release for the former purposes to drive turbines and generators. At the present time we have 13 hydro-electric power plants with an installed capacity of 711,000 kilowatts equal to 16% of our national total. There are about 110 potential dams ites in the country, which could yield about 2,300,000 kilowatts of hydro-electric power. There are about 54 sites suitable for pumped storage which could produce a further 38,600,000 kilowatts of power. All available if we carefully develop our water resources. To summarize, water resource development is essential to the regional development program and the welfare of our people, it must proceed hand-in-hand with other aspects of regional development such as land impovement, high way extension, development of our forests, erosion control, and develop ment of heavy and chemical industries. Through the successful implementation of such an integrated regional development program, we can look forward to a period of national strength, and due recognition of our country by the worlds societies.

  • PDF

전자만화의 타이밍 에이전시 : 멀티미디어와 혼합된 만화를 중심으로 (Timing Agency in Digital Comics : Focused on Multimedia Comics)

  • 여미주
    • 만화애니메이션 연구
    • /
    • 통권27호
    • /
    • pp.79-97
    • /
    • 2012
  • 만화책을 읽을 때 드는 시간은 제각각이다. 이는 독자의 주관으로 만화속의 시간이 해석됨을 의미한다. 물론 만화의 시스템 안에서 시간성, 즉 만화의 타이밍을 조절하기 위해 여러 가지 장치를 만화 안에 배치시키는 것은 작가지만, 만화에 몰입하여 그 시간 감각을 읽고 상상하는 일은 독자의 몫이다. 즉, 종이만화에서 일반적으로 만화의 타이밍을 주관하는 주체는 독자였다. 반면 종이만화에서 전자만화로 매체가 바뀌게 되면서 새롭게 포착되는 현상은, 독자의 상대시간에 작가가 개입하여 절대시간으로 이행되는 양상이다. 게임 매체에서의 에이전시 이론에 따르면, 에이전시란 게임 안에서 독자가 할 수 있는 일을 재현해주는 게임 속의 대행을 의미하며 그에 수반되는 강제성으로 하여금 게임에 만족할 수 있게 한다. 전자만화 중 일부, 애니메이션이나 게임 등의 매체의 성격을 흡수한 형태의 전자만화에서는 출판만화에서 독자가 누릴 수 있었던 주관적인 타이밍이 작가에게 이행되는 경우를 볼 수 있다. 전자만화에서의 질료적 제약인 서사의 질 혹은 정보량, 형상적 제약인 조작이 균형을 이루어야 타이밍 에이전시가 높아진다. 적절한 에이전시는 전자만화의 가독성을 높이지만, 서사와 조작 사이의 불균형은 독자의 타이밍 에이전시를 빼앗게 된다. 멀티미디어와 혼합된 전자만화를 연출할 때 그 점 역시 고려하여야 할 것이다.

Mitigation of Methane Emission and Energy Recycling in Animal Agricultural Systems

  • Takahashi, J.;Mwenya, B.;Santoso, B.;Sar, C.;Umetsu, K.;Kishimoto, T.;Nishizaki, K.;Kimura, K.;Hamamoto, O.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제18권8호
    • /
    • pp.1199-1208
    • /
    • 2005
  • Abatement of greenhouse gas emitted from ruminants and promotion of biogas energy from animal effluent were comprehensively examined in each anaerobic fermentation reactor and animal experiments. Moreover, the energy conversion efficiency of biomass energy to power generation were evaluated with a gas engine generator or proton exchange membrane fuel cell (PEMFC). To mitigate safely rumen methanogenesis with nutritional manipulation the suppressing effects of some strains of lactic acid bacteria and yeast, bacteriocin, $\beta$1-4 galactooligosaccharide, plant extracts (Yucca schidigera and Quillaja saponarea), L-cysteine and/or nitrate on rumen methane emission were compared with antibiotics. For in vitro trials, cumulative methane production was evaluated using the continuous fermented gas qualification system inoculated with the strained rumen fluid from rumen fistulated Holstein cows. For in vivo, four sequential ventilated head cages equipped with a fully automated gas analyzing system were used to examine the manipulating effects of $\beta$1-4 galactooligosaccharide, lactic acid bacteria (Leuconostoc mesenteroides subsp. mesenteroides), yeast (Trichosporon serticeum), nisin and Yucca schidigera and/or nitrate on rumen methanogenesis. Furthermore, biogas energy recycled from animal effluent was evaluated with anaerobic bioreactors. Utilization of recycled energy as fuel for a co-generator and fuel cell was tested in the thermophilic biogas plant system. From the results of in vitro and in vivo trials, nitrate was shown to be a strong methane suppressor, although nitrate per se is hazardous. L-cysteine could remove this risk. $\beta$1-4 galactooligosaccharide, Candida kefyr, nisin, Yucca schidigera and Quillaja saponarea are thought to possibly control methanogenesis in the rumen. It is possible to simulate the available energy recycled through animal effluent from feed energy resources by making total energy balance sheets of the process from feed energy to recycled energy.

영양교육과 운동중재 프로그램이 성인비만여성의 신체성분과 식이섭취, 혈중지질 및 기초체력에 미치는 효과 (2) - 비만관리 프로그램의 참여율과 프로그램 효과와의 상관성 - (The Effect of Nutrition Education and Excercise Program on Body Composition and Dietary Intakes, Blood Lipid and Physical Fitness in Obese Women (2) - Relationship between Participation Rates and Effectiveness of Obesity Management Program -)

  • 이희승;이지원;김지명;장남수
    • Journal of Nutrition and Health
    • /
    • 제43권3호
    • /
    • pp.260-272
    • /
    • 2010
  • This study examined how the participation rates contribute to subjects' outcomes after a nutrition education (once/week) and exercise (3 times/week) intervention program for 12 weeks in 44 obese female subjects. The subjects were divided into two groups: high-participator (HP) or low-participator (LP) groups according to their participation levels based on the median visit value (30 visits out of a total of 48 visits). Daily nutrient intakes assessed by a 24-hour recall, body composition, blood lipid profiles and physical fitness were measured at baseline and after 12 weeks. After the intervention, weight, BMI, percent body fat, and the waist-hip ratio were significantly decreased in the HP group. In addition, the HP group had a greater rates of changes in weight (HP group: -6.6% and LP group: -3.1%, p < 0.01), BMI (-7.0% and -3.2%, p < 0.01), percent body fat (-7.8% and -4.2%, p < 0.05), and waist-hip ratio (-3.1% and -0.4%, p < 0.01) compared to the LP group. Energy-adjusted protein, fiber, potassium, vitamin $B_1$, vitamin $B_6$, and vitamin C were significantly increased in the HP group. The HP group showed a significant increase in HDLcholesterol and a decrease in blood pressure, total cholesterol, LDL-cholesterol, triglycerides, and atherogenic index (AI). While the muscle endurance, muscle strength, power, agility and flexibility were significantly increased in the HP group, agility and balance were improved in the LP group. In addition, dietary behavior score was significantly increased and stress score decreased in the HP group compared to the LP group. High participation rates were correlated with the improvement of the nutrient density (protein, fiber, potassium, Vitamin $B_1$, Vitamin $B_2$, Vitamin $B_6$ and folate), anthropometric parameters (body weight, BMI and percent body fat), serum lipid profiles (HDL-cholesterol, Triglyceride, and AI) and physical fitness (muscle endurance) adjusted for age, menopausal status, alcohol drinking, nutritional supplement use and baseline BMI. Our results suggest that high participation in nutrition education and exercise program was effective not only for weight reduction but also for the improvement of physical fitness in obese women.