• 현장농수산연구지
• /
• 제10권1호
• /
• pp.153-167
• /
• 2008

High temperature and natural sun light are considered as the core conditions for high quality and large quantity of Phellinus baumii production. However still now on there has been a mistake of excessively cutting off the natural light by spreading the closing nets on the mushroom cultivating house. For an example there are many houses where the closing nets under the roofs be extended to cover the sides of the houses, which way prevents the mushrooms in the houses from receiving sufficient natural sun light and getting the temperature sufficiently to grow so that the quantity and quality of the produced mushrooms are lowered even though the mushrooms can grow in those conditions. In order to avoid this mistake, the closing nets must be placed on the roofs of the houses only without dropping them to cover the sides. Further more when the closing nets are placed triply at the beginning stage of Phellinus baumii's growth in the house, the nets restrain the internal temperature of the house going up and intercept the natural bright light flowing into the house so that the growing tardiness occur to the Phellinus baumii. Therefore the roof only must have been covered by the closing net for 65% cutting off the light until May, and then covered by double folded the net for June, triple folded the net for July and August, double folded the net for September, and the single net for October. When the ventilation in the house has been maintained until the house tightly balloon out through controling lifting force of internal air, the Phellinus baumii can grow well while the bed logs themselves aren't dried out. Marketing is also very much important as well as increasing quality and quantity of Phellinus baumii production.

• 한국토양비료학회지
• /
• 제45권6호
• /
• pp.1179-1186
• /
• 2012

For better understanding of carbon cycle dynamics of an agro-ecosystem, an accurate assessment of seasonal and daily $CO_2$ flux is essential to understand the relationship between various environmental factors and crop productivity. We developed the automatic sliding canopy chamber (ASCC) system that measured continuous net ecosystem productivity (NEP) over whole growing season under the natural meteorological rhythm. The ASCC was composed of two main parts which were sliding part for measuring NEP, and automatic opening and closing chamber (AOCC) for measuring soil respiration (SR) on the soil surface. The ASCC was developed by using open flow method for measuring soil $CO_2$ efflux. The disturbance of natural meteorological condition was minimized by opening the base frames. In the field test with barley (Hordeum vulgare L.), NEP was calculated at $140mg\;CO_2\;m^{-2}h^{-1}$ on a clear day using continuous data and eliminated the possibility of overestimate about 16% using one hour data during the day time. Unlike other small scale chamber system, installation on cropping-field made it possible to take any modifications which might be caused by natural environmental condition.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 추계학술대회 논문집
• /
• pp.197-198
• /
• 2008

The forging process produces complicated and designed components in a die at high productivity for mass production and minimizes the machining amount for favorable material utilization; the forging products used at highly stressed sections are well accepted at a wide range of industry such as automobile, aerospace, electric appliance and et cetera. Accordingly, recent R&D activities have been emphasized on improvement of forging die-life and near net shaping technology for cost effectiveness and better performance. Usually closing and consolidation of internal void defects in a ingot is a vital matter when utilized as large forged products. It is important to develop cogging process for improvement of internal soundness without a void defect and cost reduction by solid forging alone with limited press capacity. For experiments of cogging process, hydraulic press with a capacity of 800 ton was used together with a small manipulator which was made for rotation and overlapping of a billet. Size of a void was categorized into two types; ${\phi}$ 6.0 mm and ${\phi}$ 9.0 mm to investigate the change of closing and consolidation of void defects existed in the large ingot during the cogging process. In addition for forming experiment of piston grown air drop hammer with a capacity of 16 ton was used. The experiment with piston crown was carried out to show the formability and void closing status. In this paper systematic configuration for closing process of void defects were expressed based on this experiment results in the cogging process. Also forging defects through forming process for piston crown was improved using the experiment results and FE analysis. Consequently this paper deals with the effect of radial parameters in cogging process on a void closure far large forged products and formability of piston crown.

• 경영과정보연구
• /
• 제30권4호
• /
• pp.23-44
• /
• 2011

본 논문은 우리나라 주식시장을 대상으로 2003년 1월 2일부터 2011년 4월 30일까지 일별자료를 이용하여 외국인 및 기관투자자의 순매수강도가 주식수익률에 영향을 미치는 지에 대해 금융위기 전 후로 구분하여 분석하였다. 우선 t일의 close to close 수익률은 전체기간에 대해 t-1일의 외국인 및 기관투자자의 순매수강도에 의해 통계적으로 유의하게 음(-)의 영향을 받았으며, 동시차에서는 양(+)의 방향으로 영향을 받는 것으로 나타났다. 하위기간인 금융위기 전 후에 대한 분석에서도 전체기간과 별다른 차이점은 발견되지 않았다. close to open 수익률을 이용한 분석에서는 전체기간과 하위기간 모두에 대해 t-1일의 외국인 및 기관투자자의 순매수강도는 t일의 close to open 수익률에 양(+)의 영향을 미치는 것으로 나타났다. 마지막으로 open to close 수익률을 이용한 분석에서 전체기간의 경우 t-1일의 외국인 순매수강도라는 정보는 당일의 시초가가 형성된 이후에 영향력이 사라지는 것으로 나타났고, 기관투자자의 순매수강도는 시초가 형성 이후에 음(-)의 영향을 준다는 사실이 발견되었다. 본 연구에서는 close to close 수익률을 close to open와 open to close 수익률로 분해하여 분석함으로써 외국인 및 기관투자자의 투자행태가 주식수익률에 미치는 영향에 대해 보다 구체적인 결과를 얻을 수 있었다.

• Nuclear Engineering and Technology
• /
• 제54권5호
• /
• pp.1674-1685
• /
• 2022

The ball valve is an important device in the pipeline transportation system of nuclear power plants. Its operational stability and safety directly affect the normal working of nuclear power plants. In this study, the transient numerical simulation of the opening and closing process of a ball valve was conducted on the basis of the flow interruption capability experiment of the ball valve by using the moving mesh method and inlet and outlet variable boundary conditions. The flow rate and pressure difference with time of the opening and closing process of the ball valve were studied. The internal flow characteristics of the ball valve under different relative openings were analyzed in conjunction with the typical back-step flow structure. Results show that the transient numerical results agree well with the experimental results. The internal flow characteristics of the ball valve are similar at the same opening during opening and closing process. At small opening, the spool and outlet channels easily form a back-step flow structure. The disappearance and generation of backflow vortices during opening and closing occur at 85% opening and 75% opening, respectively. With the decrease in opening degree, the difference in vortex core area in the flow channel of the ball valve spool in the opening and closing process gradually appears. The research results provide some reference value for the design and optimization of ball valves.

• 수산해양기술연구
• /
• 제43권4호
• /
• pp.347-354
• /
• 2007

This paper describes on the real-time monitoring of net setting and hauling process for fishing operations of Danish seine vessels in the southern waters of Korea as an application of a PC based ECDIS system. Tracking of fishing process was performed for the large scale Danish seine vessel of G/T 90 and 350 PS class using the fishing gear which the length of net, ground rope, head rope and sweep line including warp in both sides were 86m, 104m, 118m and 3,200m, respectively. Tracking information for net setting and hauling process was continuously recorded for 23 fishing operations performed on November and December, 2003. All measurement data, such as trawl position, heading, towing course and past track which was individually time stamped during data acquisition, was processed in real time on the ECDIS and displayed simultaneously on the ENC chart. The results indicated that after the separation of a marker buoy from Danish seiner, the averaged running speed of vessel and the averaged setting period while shooting the seine on the course of diamond shape to surround the fish school in the 23 fishing operations were 8.3 knots and 13.1 minutes, respectively. And with the maker buoy taken on board, the averaged running speed of vessel and the averaged towing period while closing the seine on the straight route was 1.0 knots and 47.0 minutes, respectively. After the closing stage of hand rope, the hand rope was towed by the averaged speed of 2.2 knots during the 13.0 minutes. The average area for route of diamond shape swept by sweep lines of the seine in 23 fishing grounds was $709,951.6m^2$. Further investigation is also planed to provide more quantitative tracking information and to achieve more effective surveillance and control of Danish seine vessels in EEZ fishing grounds.

• 한국유기농업학회지
• /
• 제28권1호
• /
• pp.59-68
• /
• 2020

This study analyzed and suggested management situations and improving issues on a consumer cooperatives which has supplied environmentally friendly agricultural products from the year 2002. Indices of management analysis are stability ratio, activity ratio and profitability ratio. Management Stability ratio indices are debt ratio, net worth ratio, fixed ratio and current ratio. Management activity ratio ones include fixed assets turnover and net worth turnover. And profitability ratio is showed through return on investment, net return on sales and return on equity. In order to analyze these indices, financial statements after the closing entires are used each year.

• Nuclear Engineering and Technology
• /
• 제56권3호
• /
• pp.966-972
• /
• 2024

Idaho National Laboratory (INL) announced at COP27 it would reach net zero greenhouse gas (GHG) emissions by 2031. As a Nuclear, Energy and Environment, and National Homeland Security laboratory, the predominant solution to closing the clean energy gap will include nuclear as a safe, clean, reliable and affordable electricity source with the additional benefit of producing heat and hydrogen to fuel INL's large transportation fleet. INL's collaboration first vs. competition is essential to the program's success. The focused actions in INL's Nuclear Roadmap include: Infrastructure, Licensing/Regulatory, Financial, Time to Market, Fuel Cycle and Public Confidence/Communications. The roadmap also includes nuclear technology innovations and creative partnerships with utility providers, regulators, businesses, community members, and Indigenous Peoples to accelerate deployment of advanced reactors. Through development of the Net-Zero Nuclear Roadmap, INL will offer a model to provide safe and secure energy for the nation and the world by: (1) establishing the necessary infrastructure on its 890-square mile site to support demonstration, (2) showing proven pathways through the licensing and regulation process, (3) partnering with utilities to ensure commercial application, and (4) collaborating with industry to site new technologies.

• 경영과정보연구
• /
• 제31권4호
• /
• pp.593-609
• /
• 2012

본 연구는 우리나라 주식시장을 대상으로 2004년 1월 2일부터 2012년 8월 31일까지 일별자료를 이용하여 외국인투자자 거래행태의 대용치인 순매수강도의 비기대변동성이 KOSPI 일별종가수익률, 밤수익률 그리고 낮수익률의 변동성에 대해 정보이전효과가 존재하는 지에 대해 금융위기 전 후로 구분하여 분석하였다. 분석결과에 의하면 전체 분석기간 및 금융위기 전 후 하위기간 동안 전일(t-1) 및 당일(t) 외국인투자자 순매수강도의 비기대변동성이 KOSPI 일별종가수익률 변동성에 대해 각각 음(-)과 양(+)의 정보이전효과가 있는 것으로 나타났다. 여기서 음(-)의 정보이전효과는 전일 외국인투자자 순매수강도의 비기대변동성이 다음날 주식수익률의 변동성을 감소시키는 역할을 하고 있음을 의미하고 양(+)의 정보이전효과는 당일 외국인투자자 순매수강도의 비기대변동성이 당일 주식시장의 변동성 크기를 증가시킨다는 것을 의미한다. 한편, 전일 외국인투자자 순매수강도의 비기대변동성은 밤수익률의 변동성에 대해 정보이전 효과가 없는 것으로 나타났다. 마지막으로 낮수익률의 변동성에 대한 외국인투자자 비기대변동성의 정보이전 효과는 전체기간과 동일한 결과를 보였다.

• Nuclear Engineering and Technology
• /
• 제49권1호
• /
• pp.254-266
• /
• 2017

Finite-element analysis based on elastic-perfectly plastic material was conducted to examine the influence of structural deformations on collapse loads of circumferential through-wall critically cracked $90^{\circ}$ pipe bends undergoing in-plane closing bending and internal pressure. The critical crack is defined for a through-wall circumferential crack at the extrados with a subtended angle below which there is no weakening effect on collapse moment of elbows subjected to in-plane closing bending. Elliptical and semioval cross sections were postulated at the bend regions and compared. Twice-elastic-slope method was utilized to obtain the collapse loads. Structural deformations, namely, ovality and thinning, were each varied from 0% to 20% in steps of 5% and the normalized internal pressure was varied from 0.2 to 0.6. Results indicate that elliptic cross sections were suitable for pipe ratios 5 and 10, whereas for pipe ratio 20, semioval cross sections gave satisfactory solutions. The effect of ovality on collapse loads is significant, although it cancelled out at a certain value of applied internal pressure. Thinning had a negligible effect on collapse loads of bends with crack geometries considered.