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        검색결과 413

        401.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        402.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        U.S. organic farming has grown rapidly-20 percent or more annually-throughout the 1990s, which kept pace with consumer demand for organically produced food. Thus certified organic acreage is the total to 2.35 million acres in 48 state in 2001, and so the U.S. ranked fourth in land area managed under organic farming systems. And according to several surveys, consumer’s reasons for purchasing organic food are health and nutrition, taste and environmental concerns. California and North Dakota were the top two states in 2001 for certified organic cropland; the former with mostly fruits and vegetables, and the latter with wheat, soybeans, and other crops. And the top two states for certified organic pasture were Colorado and Texas. And then several states such as Iowa and Minnesota have begun subsidizing conversion to organic farming systems as a way to capture the environmental benefits of these systems. The price of organic produce fluctuates rather broadly because of being traded by market economy principle and of demandsupply disequilibrium. Nevertheless, average price premiums for organic produce are higher than the prices for the produce under conventional farming. Future prospects for U.S. organic farming are as follows; Demand for organically grown foods is expected to continue growing at a rapid pace, as more growers convert to organic production and more processors and distributors expand organic selections in their product lines. And new processed products and new types of healthy foods are likely to appear on the market, and some new organic products will be aimed at mainstream markets.
        403.
        2004.03 KCI 등재 서비스 종료(열람 제한)
        Farm economy is getting worse because of the free trade trends in agriculture sector and unreasonable application of market economy principles to agricultural products. And The worldwide issues of environmental pollution as well as want of food, water and energy make human future be anxious. In addition, consumers raise questions in argument about safety of foods produced by traditional farming or imported. So I propose the urban-rural living community movement(URLCM) as an alternative plan for sustainable domestic agriculture. URLCM based on environmentally friendly agriculture and community consciousness will be able to solve many of present issues on agriculture and rural society through incessant interchanges between urban and rural community. This URLCM has to be basically founded on principles of symbiosis-coexistence and life circulation. So those that have to be driven forward are organizing producers and consumer cooperatives, making environmentally friendly rural region and products, combining with consumer cooperatives, training the participants and so forth.
        404.
        2003.09 KCI 등재 서비스 종료(열람 제한)
        Environmental-friendly agriculture(EFA) has been mainly developed at many areas which have factors of natural, social cultural and economic characteristics. These rural areas can be developed into environmental-friendly space to preserve ecosystem, natural and cultural scenery, and environmental resources. The plan for developing a regional agriculture has to get central operating bodies, producers" organizations, a homogeneous district for farming, and so on. This case study is focused on development directions and situations of the EFA of Kosam area in Anseong. Kosam cooperatives is a central managing body to produce and sell rice by duck-farming method, and to develop rural area. This cooperatives is one of the leading those that have developed the regional agriculture in Korea. Kosam area is at a disadvantage of natural -geographical conditions and farming size. Kosam cooperatives has been trying to overcome these agricultural weaknesses by introducing duck-farming method. They have got many excellent results through developing EFA as a regional agriculture. Kosam area will be a good place for green tourism if they can actualize the combination model of three demand factors (natural and agricultural scenic view, natural-friendly recreation and safe food) for green tourism in the near future.
        406.
        2000.09 서비스 종료(열람 제한)
        Today the pedestrian-related problems a key subject requiring the attention of the traffic engineers for improving the transportation system. Particularly in urban and CBD locations, the pedestrian presents an element of sharp conflict with vehicular traffic. Therefore pedestrian movements must be studied for the purpose of providing guideline for the design and operation of walking transportation systems. This paper is to address the characteristics of walking transportation in a big city. Especially the focuses are emphasized on the ratio occupied by pedestrian traffic among the whole unlinked trips in a city and walking time. The data for analysis are collected in Seoul metropolitan city through sampling 1,006 citizens. Compared with other similar research works this paper utilized diversified tools to acquire more useful results. Finally, policy directions for pedestrian environment improvement were suggested.
        408.
        1999.02 KCI 등재 서비스 종료(열람 제한)
        412.
        1995.08 KCI 등재 서비스 종료(열람 제한)
        When an automatic course keeping is introduced, as is quite popular in modern navigation, the closed-loop control system consists of autopilot device, power unit, steering gear, ship dynamics, and magnetic or gyrocompass. We derive mathematical models of each element of the automatic steering system. We provide a method of theoretical analysis on the propulsive energy loss related to automatic steering of ships in the open seas, taking account of the on-off(non-linear) characteristics of power unit. Also we paid attention to non-linear element installed in autopilot device, which is normally called weather adjuster. Next we make numerical calculation of the effects of autopilot control constants on the propulsive energy loss for two kinds of ship, a fishing boat and an ore carrier. Realistic sea and wind disturbances are employed in the calculation.
        413.
        1990.06 KCI 등재 서비스 종료(열람 제한)
        Recently, there is a tendency to design the large full ships with lower-powered engine as the means for energy saving in ship's navigation at seas. Such a lower-powered ship is anticipated to show the different propulsive performance in rough seas, because the fluctuation of main engine load of lower powered ship is relatively large as compared with higher-powered ship is relatively large as compared with higher-powered ship. The fluctuation of propeller load is nonlinear at racing condition in waves. It is due to the variation of inflow velocity into propeller, the propeller immersion and the characteristics of engine governor. In this paper, the theoretical calculation of the nominal speed loss and the numerical simulation for the nonlinear load fluctuation of a model ship in rough seas are carried out. From the results of calculation, the following are discussed. (1) The ratio of nominal speed loss to the speed in still water. (2) The manoeuvring ability of ship and the operational ability of main engine in a seaway. (3) A method of the evaluation for the fluctuation of propeller torque and revolution on the engine characteristics plane. (4) The effect of engine governor characteristics on the propeller load fluctuation.
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