• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.46 no.6
• /
• pp.868-877
• /
• 2013

To understand the effects of marine environmental and meteorological parameters on laver Porphyra yezoensis production at Nakdong River Estuary, we analyzed marine environmental (water temperature, salinity, nutrients, etc.) and meteorological properties (air temperature, wind speed, precipitation, sunshine hours) with yearly and monthly variations in laver production over 10 years (2003-2013). Air and water temperature, wind speed, sunshine hours and precipitation were major factors affecting yearly variability in laver production at the Nakdong River Estuary. Lower air and water temperatures together with higher levels of nutrients and sunshine and stronger wind speeds resulted in higher laver harvests. Salinity and nitrogen did not show clear correlations with laver production, mainly due to the plentiful supply of nitrogen from river discharge and the low frequency of environmental measurements, which resulted in low statistical confidence. However, environmental factors affecting monthly laver production were related to the life cycle (culturing stage) of Porphyra yezoensis and were somewhat different from factors affecting annual laver production. In November, a young laver needs lower water temperatures for rapid growth, while a mature laver needs much stronger winds and more sunshine, as well as lower temperatures for massive production and effective photosynthesis, mostly in December and January. However, in spring (March), more stable environments with fewer fluctuations in air temperature are needed to sustain the production of newly deployed culture-nets ($2^{nd}$ time culture). These results indicate that rapid changes in weather and marine environments caused by global climate change will negatively affect laver production and, thus, to sustain the yield of and predict future variability in laver production at the Nakdong River estuary, environmental variation around laver culturing farms needs to be monitored with high resolution in space and time.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.49 no.4
• /
• pp.3-12
• /
• 2007

The purpose of this paper is to analyze the relationship between meteorological factors and agricultural reservoir storage, and predict the reservoir storage by multiple regression equation selected by high correlated meteorological factors. Two agricultural reservoirs (Geumgwang and Gosam) located in the upsteam of Gongdo water level gauging station of Anseong-cheon watershed were selected. Monthly reservoir storage data and meteorological data in Suwon weather station of 21 years (1985-2005) were collected. Three cases of correlation (case 1: yearly mean, case 2: seasonal mean dividing a year into 3 periods, and case 3: lagging the reservoir storage from 1 month to 3 months under the condition of case 2) were examined using 8 meteorological factors (precipitation, mean/maximum/minimum temperature, relative humidity, sunshine hour, wind velocity and evaporation). From the correlation analysis, 4 high correlated meteorological factors were selected, and multiple regression was executed for each case. The determination coefficient ($R^{2}$) of predicted reservoir storage for case 1 showed 0.45 and 0.49 for Geumgwang and Gosam reservoir respectively. The predicted reservoir storage for case 2 showed the highest $R^{2}$ of 0.46 and 0.56 respectively in the period of April to June. The predicted reservoir storage for 1 month lag of case 3 showed the $R^{2}$ of 0.68 and 0.85 respectively for the period of April to June. The results showed that the status of agricultural reservoir storage could be expressed with couple of meteorological factors. The prediction enhanced when the storage data are divided into periods rather than yearly mean and especially from the beginning time of paddy irrigation (April) to high decrease of reservoir storage (June) before Jangma.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.23 no.7
• /
• pp.492-497
• /
• 2011

The objective of this research is to study the variation of optimum slope angles of collectors for seven regions in Korea, which are Seoul, Gangneung, Daejeon, Daegu, Gwangju, Busan and Jeju. The results for 2000~2007 are analyzed to sec if adjustment of slope angles is necessary each year to receive maximum solar radiation. For an azimuth fixed solar collector, solar radiation of yearly optimized slope angle during May~Sept.(summer), Nov.~Mar.(winter) and the whole year are greater than the fixed slope angle by 0.03%, 0.02%, and 0.04%, respectively. For an azimuth tracking solar collector, solar radiation of yearly optimized slope angle during May~Sept.(slimmer), Nov.-Mar.(winter) and the whole year are greater than the fixed slope angle by 0.03%, 0.07%, and 0.04% respectively. It is unnecessary to adjust slope angles each year for both azimuth fixed and tracking collectors, since the gains are insignificant. Solar radiation of the azimuth tracking solar collector during May~Sept., Nov.~Mar. and the whole year are greater by 14.7%, 16.0%, and 19.2% than the azimuth fixed solar collector.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.3
• /
• pp.779-786
• /
• 2008

This study was performed to evaluate the characteristics of current air quality and to examine the monthly and yearly variation of $SO_2,\;O_3,\;CO,\;NO_2$, and fine particulate matter(PM-10) concentration in Seosan for the period of 1998-2006. During the recent 3 years, from 2004 to 2006, the yearly mean concentration of $SO_2,\;NO_2$, and PM-10 remained stability but CO and $O_3$ are gradually decreased. The monthly mean concentration of $NO_2$, CO, and $SO_2$ were high in the winter season and decreased steadily to the summer season, but the maximum concentration of $O_3$ and PM-10 appeared in the springtime. The number of days exceeding 24-hour standards for PM-10 were 54 times at Dokgodri and 25 times at Dongmundong. The number of sampling days exceeding the 1-hour and 8-hour standards for $O_3$ were 68 and 210 times at Dongmundong and at Dokgotri 93 and 213 times, respectively.

• Journal of the Korean housing association
• /
• v.13 no.2
• /
• pp.1-6
• /
• 2002

As a result of rapid economic and social change, the number of large-scale builing is expected to increase. In response to the growing increase, It will be a greater demand for up-to-date for heating and cooling, illumination, communication and disaster protection system as well as a sharp rise in overall energy consumption. Gradually the living of apartment building is increasing by growing population. In basic data will be offered for the energy conservation programs, and establishing some standards for the energy consumption in future. By understanding how energy sources are actually utilized in existing apartment houses, we can develop more appropriate strategies to maximize both the efficient use of energy and its conservation.

• Journal of the Korean Society of Safety
• /
• v.14 no.4
• /
• pp.176-181
• /
• 1999

The objective of this study is to compare and analyze the industrial injury-values of all the industries through yearly accident rate and frequency rate based on the governmental documentation of industrial injuries. The samples for this study are chosen from the companies with less than 200 employees under charge of the Kangnung Ministry of Labor during the period of 1995-97. Safe-T-Score is used for statistic control on the qualitative comparison of the present and the past industrial injury-rates. In the comparison of the past and the present industrial injury-rate by means of Safe-T-Score, this study shows that there does not exist any remarkable improvement, whereas the document of the Ministry of labor reports that the rate is decreasing greatly. Therefore, this study proposes some solutions to reduce industrial disasters and points out the necessity of more practical and effective methods to analyze the industrial disaster.

• Journal of the Korean Chemical Society
• /
• v.15 no.6
• /
• pp.370-377
• /
• 1971

The Carbon-14 content in surface air at Seoul, Korea, was measured from February 1970 to August 1971 and a Larix Leptolepis, Gordon tree (Ip-Gal Namu) grown at Kwang-Nung, Kyunggi-Do, Korea, having 37 growth rings, was assayde for $^{14}C$. From the results of the surface air study, it was calculated that during the above period the inventory of excess $^{14}C$ in the atmosphere decreased with a half-time of 4.6 years. The overall yearly decrease was also checked. The tree-ring study showed that the tree's atmosphere was affected by $^{14}C$ from nuclear tests after 1956. In one study, atmospheric $CO^2$ samples were collected bi-monthly by the absorption of $CO^2$ in alkaline hydroxide solution. In the other, 5 year annual growth rings were assayed for radiocarbon. For the radioactivity measurement, carbon atoms in samples were converted to carbon atoms of benzene. The resulting benzene was taken as primary solvent for liquid scintillation counting.

• Journal of Korean Society for Atmospheric Environment
• /
• v.10 no.4
• /
• pp.245-251
• /
• 1994

We considered that characteristics of SO$_2$, concentration level and relations of the meteorological parameters and high pollution concentration from the data measured 7 air quality continuous monitoring stations during 4 years, from 1990 to 1993 in Pusan. The SO$_2$ concentration level showed decreasing trend yearly, it was maximum in Winter, minimum in Summer. The time of SO$_2$ peak concentration lagged from seashore to land because of break-down of the nocturnal inversion layer and seabreeze. Ihe correlations of daily SO$_2$, value between various air quality continuous monitoring stations were highest between Beomcheondong and Meongryundong, lowest between Daeyeondong and Sinpyeongdong because of difference of air Pollution emission sources characteristic. The meteorological parameters affecting SO$_2$ concentration level were minimum temperature, relative humidity, wind speed and air pressure. The SO$_2$ high pollution($\geq$95ppb) occurred almost in Winter, particulaly in such day showing lower wind speed and higher air pressure. Elementary SO$_2$ high Pollution Predictor were high pressure system and stability of lower atmosphere.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.211-212
• /
• 2012

Over the years, the recovery of the domestic construction market, which does not appear on the reverse, but rather due to a surge of construction materials cost of the construction sector is experiencing greater difficulties. Cement raw materials in the manufacturing process, if some of the waste recycling, cites quality control for products and measures for the thorough management is needed. In this study, three companies of the past four years in the production of cement against doejin physical performance test results conducted yearly and seasonal trends by analyzing changes in the years to review the cement for cement to utilize as a basis for management points is.

• Journal of Korean Society for Quality Management
• /
• v.19 no.1
• /
• pp.141-150
• /
• 1991

This paper is aimed to construct a CIM(Computer Intergrated Manufacturing) model through optimal flexible manufacturing systems for factory automation in order to provide higher productivity. This paper provides a ease through an analytical method to construct flexible manufacturing systems for factory automation. The contents of this paper include forecasting of demands which analyze variation of demand using Winter's model, line balancing utilizing Lanked Positional Weight Method, and a case analysis through simulation by Monte Carlor Method. The result shows the manpower and net present value of investment have decreased 42% and 19.6%, respectively, and yearly net profit has increased 30%.