• Korean Journal of Agricultural Science
• /
• v.2 no.1
• /
• pp.151-177
• /
• 1975

To obtain the informations on the checking factors of the effecient utilization of paddies in chungnam province and study on the effecient working system and high productive cropping system in paddies, the utilization state of paddies including environmental conditions were investigated at sample 1,500 farms. The results obtained are summarized as follows; 1. The difficulty of drainage in paddies was the most important factor checking the utility of paddies. Delayed transplanting of rice and lack of labour were also important checking factors on the efficient utilization of paddies. 2. The utilization of paddies was rather effecient at small size farms of which farmers were almost poor, and most of them cultivated barley for their own food. 3. Considering climatic conditions, pre-crops of rice must be harvested before June 10 tho and the marginal transplanting date of rice plant is June 25 th. 4. In case of planting barley as a post-crop after rice, the spread seeding by rotary before plowing was most efficient with lowest cost. 5. Considering rice cultivation, yield of barley and net income, the most efficient cropping system was "Josaengtongil + Olbori".

• Journal of Korea Port Economic Association
• /
• v.30 no.4
• /
• pp.199-217
• /
• 2014

There have been relatively lots of studies on the relationships beteen port and city. And, most of the recent studies on the subject shows that the relationship between the two parties is weakening. The contributions of a port to the city economy such as convenience of logistics service utilization, cost reduction, creation of job opportunities and value added production etc. are diminishing, whereas negative effects of port such as environmental effects, limitation of waterfront activities etc. have been increasing. On the other hand, port logistics service demand from city economy is decreasing. As for Busan city, the trend of major economic indicators and growth factor analysis results show that there is hardly any relationships between the development of transportation industry(including port logistics) and the regional economy. Especially, it is identified that most regional industry sectors excluding transportation industry failed to secure competitive advantage. Accordingly, it can be concluded that Busan city economy fails to take advantage of advanced transportation industry sector, which supports overall economic activities. On the other hand, it can be a problem for enhancement of port-city relationships that related and supporting industries of transportation industry such as information and communication industry, financial and insurance industry, and processing and assembling manufacture industry fail to secure competitive advantage in Busan city.

• Plant Journal
• /
• v.9 no.3
• /
• pp.38-42
• /
• 2013

Submarine gas fields have focused because of the increasing fuel cost, the environmental regulations, and the safety & NIMBY problems. LNG-FPSO which is available for acid gas removal, recovery of the condensate & LPG and Liquefaction in topside process is one of high technology offshore structures. On the other hands, it is necessary to verify the pre-treatment efficiency by the ship motion and to apply to the design for LNG-FPSO. This study is to develop the pre-treatment technology for LNG-FPSO as taking account to the process efficiency by ship motion effects and the area optimization. Based on the simulation results, it founds that hybrid process shows the low circulate rate, the low heat duty and the small size of column dimensions compared to typical amine process. It will be verified the process efficiency in the various conditions by sea states as performing the 6-DOF motion test and CFD simulation.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.56-61
• /
• 2009

Paradigm depending only on fossil fuel for building heat source is rapidly changing. Accelerating the change, as it has been known, is obligation for reducing green house gas coming from use of fossil fuel, i.e. reaction to United Nations Framework Convention on Climate Change. In addition, factors such as high oil price, unstable supply, weapon of petroleum and oil peak, by replacing fossil fuel, contributes to advance of environmental friendly renewable energy which can be continuously reusable. Therefore, current new energy policies, beyond enhancing effectiveness of heat using equipments, are to make best efforts for national competitiveness. Our country supports 11 areas for new renewable energy including sun light, solar heat and wind power. Among those areas, ocean thermal energy specifies tidal power generation using tide of sea, wave and temperature differences, wave power generation and thermal power generation. But heat use of heat source from sea water itself has been excluded as non-utilized energy. In the future, sea water heat source which has not been used so far will be required to be specified as new renewable energy. This research is to survey local heating system in Europe using sea water, central solar heating plants, seasonal thermal energy store and to analyze large scale central solar heating plants in German. Seasonal thermal energy store necessarily need to be equipped with large scale thermal energy store. Currently operating central solar heating system is a effective method which significantly enhances sharing rate of solar heat in a way that stores excessive heat generating in summer and then replenish insufficient heat for winter. Construction cost for this system is primarily dependent on large scale seasonal heat store and this high priced heat store merely plays its role once per year. Since our country is faced with 3 directional sea, active research and development for using sea water heat as cooling and heating heat source is required for seashore villages and building units. This research suggests how to utilize new energy in a way that stores cooling heat of sea water into seasonal thermal energy store when temperature of sea water is its lowest temperature in February based on West Sea and then uses it as cooling heat source when cooling is necessary. Since this method utilizes seasonal thermal energy store from existing central solar heating plant for heating and cooling purpose respectively twice per year maximizing energy efficiency by achieving 2 seasonal thermal energy store, active research and development is necessarily required for the future.

• Journal of Korea Water Resources Association
• /
• v.39 no.5 s.166
• /
• pp.405-415
• /
• 2006

The deposition of sewer solids during dry weather in combined sewer systems results in a loss of flow capacity that may restrict flow and cause a local flooding and enhanced solids deposition. Sewer solid accumulations in drainage systems also create the 'first-flush' phenomena during wet weather runoff periods. In order to solve these problems, measurement of these loadings for a given sewer system for extended period is needed but this task is very difficult and extremely expensive. In this study, generalized procedures for estimating sewer sediment solid during dry weather in combined sewer systems developed by the U. S. Environmental Protection Agency were applied in a drainage system in Korea. As result, the appropriate equation can be selected and applied according to the available data. However, the estimated solid sediment shows considerable difference between methods which classified by model and estimation methods of variable. The estimated values using equations (1) $\sim$ (4) are greater than that of equations (5) $\sim$ (9) and intermediate models show greater values than elaborate or simplest models. The comparison between simulated and measured solid deposition is difficult due to the absent of measurement data, but this estimation method can be used usefully for the management of sewer solid with reduction of cost and effort if the measurement is carried out and the equation is adjusted according to the actual drainage systems in Korea.

• Korean Journal of Microbiology
• /
• v.50 no.4
• /
• pp.313-318
• /
• 2014

The world is in need of sustainable and eco-friendly energy sources such as microalgal biodiesel due to global warming and fossil fuel shortages. In this study, we compared the effectiveness of liquid fertilizer produced from swine manure and agriculture grade solid fertilizers as nutrient sources for microalgal biomass production. Mixed culture (Chlorella spp., Scenedesmus spp., Stigeoclonium spp.; CSS) was cultivated for 28 days in Small Scale Raceway Pond (SSRP) using various nutrient sources (swine manure liquid fertilizer, agricultural solid fertilizer, and mixture of these two fertilizers). Biomass and lipid productivity of fertilizer mixture were the highest at 0.8 g/L and 5.8 mg/L/day, respectively. These results indicate that the fertilizer mixture can provide microalgae necessary nutrient sources for stable biodiesel production and biomass growth. In addition, overall cost of microalgal cultivation and subsequently biodiesel production would be significantly reduced.

• Journal of the Korea Computer Graphics Society
• /
• v.21 no.1
• /
• pp.1-11
• /
• 2015

Researchers have developed virtual reality environments to provide audience with more visually immersive experiences than previously possible. One of the most popular solutions to build the immersive VR space is a multi-projection technique. However, utilization of multiple projectors requires large spaces, expensive cost, and accurate geometry calibration among projectors. This paper presents a novel omnidirectional projection system with a single projector and a single spherical mirror.We newly designed the simple and intuitive calibration system to define the shape of environment and the relative position of mirror/projector. For successful image projection, our optimized omnidirectional image generation step solves image distortion produced by the spherical mirror and a calibration problem produced by unknown parameters such as the shape of environment and the relative position between the mirror and the projector. Additionally, the focus correction is performed to improve the quality of the projection. The experiment results show that our method can generate the optimized image given a normal panoramic image for omnidirectional projection in a rectangular space.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.6
• /
• pp.31-40
• /
• 2015

The public housing needs maintenance administration for improvement and retainment of residential condition by means of tenants participation. However, most researchers have considered tenants as passive participants in this context. The previous studies did not comprehend perspective of tenants participation and just measured the management preference and the level of satisfaction on maintenance. This study investigates the attitudes and perceptions of tenants on participation in public housing maintenance by introduced Q method that provides a systematic and rigorous quantitative means for examining human subjectivity. The subjectivity is classified as types according to cost and benefit factors by principal components analysis and varimax rotation of the extracted factors. As a result, this study present 5 types of tenants participation and expect to discuss desirable roles of tenant and org anization in public housing maintenance.

• Journal of Environmental Policy
• /
• v.7 no.4
• /
• pp.1-34
• /
• 2008

It is recognized that RPS(Renewable Portfolio Standard) and FIT(Feed-in Tariff) are two main policy instruments to promote Renewable Electricity(RE). The Korean Government announced in 2008 that RE promotion scheme will be changed to RPS from current FIT system in 2012. But we believe RPS is inferior to FIT for promoting less developed technologies such as photovoltaics or wind power. This is because the achievement of RE promotion in countries adopting RPS is markedly worse than that in European counties or Janpan adopting FIT. If the policy change is inevitable, when considering the lessons from Japan's failure as well as supporting the less developed technologies, it is recommended that either the market should be divided into several technology and scale categories, or more RPS-Credit per kWh should be assigned to the photovoltaic and wind power than instead of letting the all technologies compete in the "open category". It is also recommended that (1) Renewable Energy Promotion Fund(tentative name) based on a part of current energy related tax revenue should be introduced, or (2) cost of supporting the Renewable Electricity should automatically be transferred into the electricity bill of electricity consumers following the German System.

• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.1
• /
• pp.133-141
• /
• 2016

Although construction of any new nuclear power projects had not been launched since mid-1970s until recently in the USA, many new nuclear power plants have been constructed in many countries with the support of their governments mainly as part of their national energy security and electric source diversification policies. For many reasons, the nuclear power industry seemed to reclaim their renaissance from the beginning of this century and the investment in the nuclear power projects draw positive concern from the private financial sector. But the global financial crisis in 2008 and subsequent economic slow-down together with tighter bank credit regulations caused commercial banks, the main source of financing, to lose appetite for investing in new nuclear power projects. But the nuclear power economics shows that the nuclear power is viable in terms of the environmental benefit and long-term average cost compared to other power generation sources. Also doubt about nuclear power safety was much mitigated due to technology development and reinforced safety-related tests and monitoring. Therefore, the prospect for nuclear power market expansion remains positive although there are comparatively big differences among different scenarios. After Korea Electric Power Corp. won the UAE nuclear power project in December of 2009, the competition in nuclear power markets is undergoing huge changes. Competitors backed by the support of their own governments are now entering the market with many aggressive and innovative financing packages to win bids of new nuclear power projects. This report analyzed the nuclear power market prospects, competitive edges of nuclear power, risk management measures, and financing challenges and recommends alternative solutions to promote competitive edges in winning bids of new nuclear power projects.