• Journal of Bio-Environment Control
• /
• v.6 no.3
• /
• pp.216-224
• /
• 1997

In the recent 10 years the protected cultivation area in Korea has been increased rapidly, and now it is very important issue to develop the heating and cooling system using the renewable energy, because the greenhouse heating and cooling cost is increased with the fossil fuel price rises. Actually the development of the cooling system is more difficult than that of the heating system, since the cooling load of greenhouse in the summer season is 2―3 times larger than the heating load in the winter season. In this study low temperature phase change materials (LTPCM) for the cold storage system were selected and developed. The theoretical and experimental analysis of thermal characteristics of LTPCM makes it possible to control the phase change temperature and stabilize the thermo-physical properties. LTPCM developed in this study has good advantages to be used as the cold storage not only for the house and working space in factory but also for the cold storage of agricultural and live-stock products.

• Journal of the Korean Institute of Rural Architecture
• /
• v.17 no.4
• /
• pp.17-24
• /
• 2015

Vacant houses are increasing across the country, but the appropriate measures have not been set up yet. Accordingly, vacant houses are left unattended for a long time, and become deserted to degrade the residential environment. They are often used as the space for the deviation of youth or even for crimes, threatening the safety of rural society. Vacant houses are not only personal properties but also public assets that form the residential environment of a town. Therefore, the problem should be better taken care of with appropriate policies. In this study, the present situation of vacant houses in Korea, the causes of the vacant house and the limits and lessons of the improvement projects were reviewed, along with the vacant house improvement systems in the UK and Japan. The most significant difference between the cases in Korea and other countries are the method of vacant house improvement. In terms of policies and support, Korea focuses on demolition, whereas other countries focus on reuse. In addition, the vacant house improvement projects in Korea are performed mostly by government agencies, whereas local governments and private organizations in other countries cooperate to improve vacant houses and go beyond mere residential environment improvement towards the local revitalization. Based on the study results, the following are proposed to efficiently improve and use the rural vacant houses. First, the Rearrangement of Agricultural and Fishing Villages Act, which allows the vacant houses to be left unattended and not improved, should be revised. Second, the intermediate support organizations that connect the demand and supply should be fostered and supported so that the use of vacant houses can be vitalized and privately led. Third, the best practices of using the vacant houses should be found and promoted, and the vacant house remodeling technique should be developed and propagated. Fourth, a special law should be enacted to comprehensively plan, support and execute the vacant house improvement, as in Japan. Finally, the value of the vacant houses as public properties should be shared in public so that all citizens can participate in addressing the vacant house issue to derive the detailed plans to solve the problem.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.18 no.2
• /
• pp.31-44
• /
• 1990

This study was carried out to investigate the changes of rural residential environmemts accompanied by the rural village improvement projects. The results of this study can be a guidoline for further betterment works of rural village envirnments. This sutdy is composed of the survey of two major parts, one Is the interview of the residents and the survey of existing conditions of residential environments, and the other is a questionnaire survey of the mental image, preference and satisfaction for each village residential environments. Based on preliminary investigation, five rural villages, located In Kyungsamgun., Kyungbuk province, were selected as sutdy sites. The major results are summarized as follows; 1. In socio-cultural enveronments, the ratio of compound and non - agricultural household are increased with the modernization of rural villages. On the ocher hand, the numbers of neighbor's association are considerably decreased. This means the traditional community of korean rural villages are diminishing. 2. In physical environments, the ratio of improved western type gouses are increased In modprnized villages. And the modernization is most remarkable in the palls of fences and gardens. 3. By the result of the analysis of residfnt's environmental image and preference, the image scores of urban, formal, mdoern, etc. are showed to be high. And the preference is also high in modernized villages. But in general, the Preference for the village environment is comparatively low in all villages. This means the improvememt work should be continuous and systematic. 4. By the result of stepwise regression analysis, the variables, affecting the preference of village environment. are regularity, familiarity, amount of greenery, beauty of surrounding scenery, convenience, cleanness, etc. The R2s of the perference models were 0.4486 ∼0.9395, Which are considered to be high. 5. In the satisfaction for each residences, the toilets are mostly dis - satisfying. With the modernization of vilelages, the needs for environmental quality by residents are increased. 6. In the satisfaction for village enveironments, the satisfaction level is most low in service facilities, such as public bath, barbershop. And the satisfaction for the scenic beauty, the amenity of surrondings, and the com munity of the traditional villages, are commparatively high in conventional villges. 7. The imporvement works, based on the characteristics of each rural villages, are recommended. And the tradition of Jung - ja tree spaces and harmony with surrounding landscape of traditional villages, must be conserved with good regards.

• Journal of Bio-Environment Control
• /
• v.20 no.1
• /
• pp.1-7
• /
• 2011

The objective of the present study is to identify the applicability of a low pressure fogging system for cooling commercial tomato greenhouse. In particular, the cooling system in this experiment utilizes low pressure spray nozzles which were developed in Korea recently. The experimental result that the temperature in fog-cooled greenhouse was lower than the non-cooled greenhouse showed the cooling effect by the low pressure fogging system. But because the relative humidity in fog-cooled greenhouse was comparatively low, the satisfactory cooling effect could be acquired by narrowing the space of fog nozzles and extending fogging time to supply more fog spray quantity. The variation of temperature distribution in fog-cooled greenhouse along timelag was insignificant during short time, but that was great during long period of day. This result showed the variation of temperature along timelag was slight by fog cooling but great by other factors like radiation, ventilation, air flow, etc. The advanced operation technology of fog system was required to reduce the variation of temperature along time lag. We plan to suggest the advanced installation and operation technology of low pressure fogging system for cooling commercial tomato greenhouse by further experiments in near future.

• Journal of Bio-Environment Control
• /
• v.20 no.2
• /
• pp.78-82
• /
• 2011

Ventilation rates, inside and outside weather data were measured in a arch-shape single-span plastic greenhouse growing tomatoes. On the roof of the experimental greenhouse, round windows which have a diameter of 0.6 m were installed at intervals of 8m. It showed that the number of air changes in this greenhouse were average 0.17 volumes per minute and in the range of 0.02 to 0.32 volumes per minute. These air changes are insufficient to meet the recommended ventilation rate for commercial greenhouses, and it is estimated that interval of 6 m is appropriate for spring or fall season. For summer season, it is necessary to narrow the space or to enlarge the open area of roof windows. Using the heat balance model, the evapotranspiration coefficients of greenhouse tomatoes were estimated from experimental ventilation data, overall heat transfer and solar radiation. It showed that the evapotranspiration coefficients were average 0.62 and in the 0.39 to 0.85 range. We suggest applying 0.6 as the evapotranspiration coefficient in design of ventilation for the single-span tomato greenhouses.

• Journal of Biosystems Engineering
• /
• v.2 no.2
• /
• pp.37-45
• /
• 1977

Solar energy is a potential source of power that offers much promise being used for low-temperature applications like drying farm crops, space heating, and water heating for domestic uses. Already much of it are being used for those purpose in foreign countries. However, very little research has been done to determine the possibility of using the solar energy in Korea. This study was conducted to develop the general prediction equation of the total radiation on a horizontal surface in Daejeon area based on 5 years 91972, Jun.1-1976. Dec.31) meteorological data (bright sunshine hours, average total horizontal radiation), and to obtain experimentally the thermal efficiency of solar air and water collectors, which will be used as a basic data of designing flat-plate solar collector system.In addition to the thermal efficiency of the collectorsthe relationship among those factors affecting it such as weather condition, orientation factor, and tilted angle of collector was analyzed. The results of this study were as follows. 1. The general predicted equation of the total radiation on a horizontal surface in Daejeon area based on bright sunshine hours was developed as $H_{av} =(1.546\frac{n}{N}-0.582)H_o$. Predicting the total radiation on a horizontal surface by the above equation was thought to be possible because to values of 0.882 was smaller than any t values at above 0.05 level on the basis of two tailed test of the difference between the calculated and the recorded values. 2.It was observed that optimum tilt angle of the collector in the summer and the autumn drying season was 13 degrees and 51 degrees respectively, these values could be obtained by adding or substracting approximately 25 degrees from the latitude of this area $(36.3^{\circ}N)$ .The relationship between orientation factor and declination of sun at suitable tilt angle of 33 degrees $(s=0.9\O)$ was shown at Fig.4. 3.The thermal efficiency of solar wdter collector was shown 13.4-51. 6% on Aug. 15 (the minimum radiation recorded) and 43.8 ~537% Aug.20 (the maximum radiation recorded), and 13.8~ 46.6 and 44.3~ 49.7 were shown on each corresponding day. 4.The thermal efficiency of the collectors according to the weather condition was shown a big difference of about 10% between the day of the maximum radiation recorded and the minimum, but the differen of efficiency between the air and the water collector was at most 2 ~ 3%. 5. Even if the efficiency of the solar water collector was a little higher than the solar air collector, for drying farm products, the solar air collector was thought to be more effective because the air heated by collector could be directly used for drying them.

• Current Research on Agriculture and Life Sciences
• /
• v.3
• /
• pp.190-196
• /
• 1985

In order to know the effects of ginseng on the stress, histochemical and electron microsbopic observations were carried out of the adrenal cortex on the stressed rats. The experiments were carried out as follow : non-stressed after saline injection (S-NS-AD), stressed after saline injection (S-S-AD), non-stressed after ginseng injection (G-NS-AD), stressed after ginseng injection (G-S-AD). Saline and ginseng extract were treated by peritoneal injection for 30 days. The results obtained are summarized as follows : Histologically a number of small lipid droplets are found more in S-S-AD group than in S-NS-AD group, whereas in ginseng treated groups numerous large lipid droplets are found. Histochemically cholesterol and its ester, glycolipid, phospholipid and glycogen are highly found in ginseng-treated groups. On the other hand, glycogen and cholesterol are also observed in S-S-AD group. Electron microscopically a numbers of lipid droplets are observed in S-S-AD, G-NS-AD and G-S-AD group, especially large lipid droplets and moderate glycogen are found in G-NS-AD and G-S-AD group. In ginseng-treated groups and S-S-AD group, dilated SER, extended intercellular space and dense bodies are observed, and the filopodiae are found in G-S-AD group. These data suggest that ginseng was activate the metabolism and synthesis of the adrenal cortical cells on the stress.

• Journal of the Korean GEO-environmental Society
• /
• v.21 no.10
• /
• pp.11-16
• /
• 2020

Korea's agricultural reservoir is one of the country's major infrastructures and plays an important role in people's lives. However, aging reservoirs are a risk for life and property. Currently, large and small dams and reservoirs have been constructed nationwide for more than 40 years of aging. Dams and reservoirs built nationwide are managed by various institutions. Therefore, it is difficult to manage all dams and reservoirs due to cost and time. Managers in the field with less management personnel and lack of expertise should be able to quickly identify risk factors for multiple reservoirs. In this study, risk factors such as seepage, leakage, settlement slide, crack and erosion were selected. To assess the risk of the items, we used the analytical hierarchical process (AHP), one of the Multi-Criteria Decision Making (MCDM) methods. The analysis showed that seepage has the greatest impact on reservoir collapse. It is judged that the priority of detailed diagnosis can be determined by evaluating the risk of dam reservoir collapse in a convenient way in advance using the calculated weight.

• Food Science and Preservation
• /
• v.12 no.2
• /
• pp.107-111
• /
• 2005

We investigated the quality of vaporized liquid of water-boiled pine needle in the aspects of drinking conformity and aroma characteristics. As a result, there was no hazardous component in the assessment for 45 types of ingredients. Especially, inorganic components such as arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) which are harmful to human body were not detected. Additionally, we observed that other ingredients were present within the standard level suitable for drinking. The total 34 volatile components of the vaporized liquid of water-boiled pine needle were identified by dynamic head-space method. Fenchol, bomeol $\beta-fenchyl$ alcohol and bomyl acetate were the major volatiles and composed of 6.7, 13.1, 26.6 and $16.2\%$ of total volatiles, respectively. In addition, the alcohols and aldehydes were the prominent ingredients of which the contents showed comparatively high.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.2
• /
• pp.353-359
• /
• 2015

This study introduces a resource recycling system in urban apartment complex using four different technologies. The four technologies, called 4G, include a production technology for reclaimed water (Green water), a biogas production technology from organic waste (Green biogas), a reuse technology of rainwater (Green rainwater), and urban agropark (Green pyramid). Green water is the technology for producing the reclaimed water from wastewater, rainwater and underground water, and the average concentrations of BOD, SS, T-N and coliform of reclaimed water were 7.8mg/L, ND (not detected), 4.9mg/L and ND, respectively. Green biogas is the technology for producing biogas and effluent after treating organic wastes (e.g. food waste and night soil) discharged from households, and the average production rates of hydrogen and methane were $0.33m^3/m^3/d$ and $0.24m^3/m^3/d$, respectively. Green pyramid, agricultural farm operated by biogas and reclaimed water, provides a healthy and recreational space for residents, and plant growth rates using treated water and reclaimed water showed height of 1.32cm and weight of 112.8g. Therefore, 4G technologies can improve the recycling rate and treatment efficiencies of waste and wastewater in an apartment complex.