• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.3
• /
• pp.129-134
• /
• 2020

Moisture infiltration inside the solar cell module, filling of EVA sheet, melting of the frame seal, and deterioration of power generation performance in the module one year after installation are occurring. Whitening phenomenon, electrode corrosion phenomenon, and dielectric breakdown phenomenon are appearing in solar cell module installed in Korea before 5-7 years, leading to deterioration of power generation performance, and big problems for long-term reliability and long life technology are emerging. Therefore, in order to solve these problems, the development of a micro inverter (MiCrco Inverter Converter, MiC) including the function of securing the durability of the solar cell module and monitoring the aging progress and the solar cell based on the monitoring data from the MiC smart monitoring programs have been proposed to determine the aging of modules. In addition, in order to become a highly efficient solar smart monitoring system through systematic operation management through IT convergence with MiC that has enhanced monitoring function of solar cell module, SoC(System On Chip) in micro inverter is the environment for solar cell module. There is a demand for functions that can detect information in a complex manner and perform communication and control when necessary. Based on these requirements, this paper aims to develop SoC-based low-cost MiC smart photovoltaic system technology.

• Journal of the Korean earth science society
• /
• v.33 no.3
• /
• pp.219-232
• /
• 2012

The intensive observation (ProbeX-2010) was performed to investigate an urban effect on summer rainfall over the Seoul metropolitan area from 13 August to 3 September 2010. Two kinds of urban effect were detected. First, weak rainfall (${\leq}1\;mm\;hr^{-1}$) was observed more frequently in the downwind area of Seoul than any other area of the country. The high frequency of weak rainfall in the downwind area was also confirmed from the recent five years of observational data (2006-2010). Because the high frequency was more apparent in mountainous regions during nighttime, the weak rainfall seems to be caused by a combined effect of urbanization and topography. Second, sporadically, a convective system was developed rapidly in the downwind area of Seoul, causing heavy rainfall (${\geq}10\;mm\;hr^{-1}$). It can be most clearly seen in series of radar images around 1300-1500 KST 27 August 2010. We investigated in detail the synoptic and local weather and upper air conditions. As a result, not only urban-induced high sensible heat but also conditionally unstable atmosphere (especially unstable in low level) and low level moisture were pointed out as important factors that contributed to urban-induced heavy rainfall.

• Culinary science and hospitality research
• /
• v.16 no.5
• /
• pp.277-286
• /
• 2010

This study examines the quality characteristics of garaedduk with roasted rice bran in addition of the control at 10%, 20%, 30% & 40% and to measure the mechanical and sensory quality characteristics in order to show the optimum addition ratio and production condition. The result of adding roasted rice bran with 10% up to 40% in all research groups are as follows; First of all, the moisture content was decreased and the "L" score which represents the brightness of garaedduk showed 68.86 in control which was non supplemented garaedduk. L-value decreased. However, a-value increased significantly and b-value increased except in control group. In the experiment on hadness, it showed 0.69 in control group and it showed 0.94 in garaedduk with 10% of roasted rice bran. Also, there was significant difference in hardness depending on the amount of roasted rice bran and storage period. In the experiment on the sensory evaluation of color and flavor in panel test, all groups showed higher scores than control group. Moreover, there was significant taste difference depending on the amount of roasted rice bran. As a test result, the overall acceptability by sensory evaluation was observed as 30%>10%>20%>40%> in the group added with roasted rice bran.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.3
• /
• pp.47-52
• /
• 2009

The comparative analysis on physico-chemical characteristics of municipal solid waste from dwelling site and landfill site were performed to provide the fundamental information of waste management in Chungju city. It was analysed and evaluated the bulk density, physical component, three major component, chemical component, and heating value of MSW. The physical components depended on the sampling site in dwelling site and landfill site. But, by the ultimate analysis, the chemical composition was almost similar to result for municipal solid waste from dwelling site and landfill site. Therefore, it is necessary to investigate the physical components according to sampling site for the MBT to introduce for combustible municipal solid waste pre-treatment, but it needs the chemical composition from landfill site to design the incinerator. The physical composition showed that the combustible and the noncombustible occupied 87.4% and 12.6% respectively. In case of three component analysis, the moisture, the combustible, and the ash were 27.6, 60.5, 11.9% respectively. The chemical composition through the element analysis were C (50.1%), H (6%), O (39.5%), N (1.9%), S (0.5%), and Cl (1.3%).

• Journal of Environmental Science International
• /
• v.27 no.5
• /
• pp.291-297
• /
• 2018

Vertical farming systems offer many advantages in urban spaces. They have also been proposed as an engineering solution to increase the productivity per unit area of cultivated land by extending crop production in the vertical dimension. However, soil water retention is a major constraint affecting the plant environment. This study analyzed the effects of growth environment of Tropaeolum majus and Fragaria spp., on the vertical farming system, by using four different types of cover material types including sphagnum moss (Control), a shading net (S.N.), multi-layered fabric (M.L.F.), and non-woven fabric (N.W.F.). The volumetric soil moisture contents and plant characteristics were investigated from May to September 2014. Plant materials were individually cultivated in hanging baskets measuring $30{\times}17{\times}17cm$, filled with a mixture of soil and perlite, and placed at 1.5m height. Each treatment was performed in quadruplicate and consisted of five plants, amounting to a total of 20 plants. The analysis indicated that different covers were associated with multiple functions and soil water retention improvements may have a positive impact on the vertical farming system. The difference in soil water retention increased in the following order: M.L.F. > Control > N.W.F. > S.N.. Furthermore, the differences in plant height and survival rate increased in the following order: M.L.F. > Control > N.W.F. > S.N. Therefore, M.L.F yielded satisfactory good response for the vertical farming system of cover materials. Our results clearly demonstrate that vertical spaces represent an attractive alternative to urban farming and suggest that further increases in yield may be achieved via different cover materials in vertical farming using hanging baskets.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.1 no.1
• /
• pp.98-107
• /
• 2005

In other to recycle the waste concrete produced in stiu on the construction and management in highway, the recycled aggregates were experimentally examined in a practical application for anti-freezing layer and lean concrete base course. From the results, the mobile impact crusher and the eccentric-mounted cone and jaw were superior to the others for the graded aggregates. In the case of anti-freezing layer, the recycled one was easily controlled since the dry densities, contrary to natural one, were not largely changed with the moisture contents. It was found that the 7days compressive strengths of lean concrete were above the 10MPa regardless of the crushing types. From the result of testing the bearing capacity of anti-freezing layer, it was found that when the recycled aggregates mixed with natural sand would be within the required gradations, the layer meets the requirements of limitation and the percentage to passing 2-20mm sieve increased by 5~13% because the flimsy mortars on aggregate were re-crushed by vibrated-roller compactor. Although the compressive strength of lean concrete was 71~85% of the natural coarse aggregate, the recycled aggregates are applicable to the lean concrete because they largely exceeded the required strength, 5.8MPa.

• Culinary science and hospitality research
• /
• v.19 no.4
• /
• pp.119-135
• /
• 2013

This study investigates waxy barley powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15% and 20%. Waxy barley powder consisted of 8.33% of moisture content, 10.47% of crude protein, 1.63% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the waxy barley powder content increased. The farinograph measurement result of the bread made with waxy barley powder showed that consistency, water absorption, development time, stability and time breakdown have increased as the waxy barley powder content increased. The amylograph measurement result of the bread made with waxy barley powder showed that T have increased as the waxy barley powder content increased. Their P, H and P-H have decreased as the ingredient contents increased. Baking loss and specific loaf volume have decreased as the waxy barley powder content increased. The chromaticity measurement result of the bread made with waxy barley powder showed no significant difference as the waxy barley powder content increased. The texture measurement result showed that the hardness and gumminess of bread have increased as the waxy barley powder content increased. Their cohesiveness, springiness and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high acceptability for the bread made with 10% waxy barley powder.

• Journal of Mushroom
• /
• v.10 no.1
• /
• pp.15-20
• /
• 2012

Ventilation effects of bottles($1,100m{\ell}$) for culturing Flammulina velutipes on its mycelial growth and mushroom production were investigated. The degree of ventilation were controlled with hole positions, upper and under, and hole sizes in the bottle lids. The ventilation effects were measured with the contents of carbon dioxide, free sugars, chitin, moisture in the bottles and with the amount of produced mushrooms from the bottles. Carbon dioxide concentrations within the culturing bottles at exponential mycelial growth period vertex were relatively high in the bottles with lids without both a sponge and an aeration hole, and in those with a smaller hole. Free sugar contents in the mycelia were the highest in those with a 47mm hole on both sides, and in those with 26~33mm holes only underside. Chitin content was the highest in those with a 26mm hole only underside. On the other hand, the lids with 42mm~47mm holes on the both sides greatly lost water and decreased the mushroom production. In conclusion, the most efficient ventilation hole sizes on the lids for bottle($1,100m{\ell}$) cultivation of Flammulina velutipes using $1,100m{\ell}$ polypropylene bottle were 19mm on both sides of the lid and 26mm on only underside. They produced more mushrooms than the control by 6~9 %.

• Korean journal of food and cookery science
• /
• v.21 no.5
• /
• pp.709-716
• /
• 2005

The aim of this study was to determine the optimal cooking conditions for astringent persimmon concentrates. With increasing time of concentration, the moisture contents and L-, a- and b-values all decreased, whereas the brix level and viscosity increased. The crude protein, fiber and ash increased and the vitamin C decreased by concentrating. The pH was the lowest at 23 hrs of boiling concentration. With longer boiling concentration time, the fructose, glucose, and sucrose levels increased but the maltose level decreased. The DPPH radical scavenging effects of astringent persimmon concentrates were more than 92%. The total phenolics, flavanol tannin, leucoanthocyanin, and chlorogenic acid levels increased with longer boiling concentration time. In the sensory evaluation of the astringent persimmon concentrates, overall acceptability was the best at the 23-hr boiling concentration. From the above results, the 23-hr boiling, astringent persimmon concentrates could be useful for cooking in terms of obtaining the high amounts of phenolic compounds as functional compounds and overall acceptability.

• Weed & Turfgrass Science
• /
• v.7 no.2
• /
• pp.111-119
• /
• 2018

This study was carried out to investigate the differences in germination and growth of Quamoclit coccinea Moench under various temperatures, seeding depths, and levels of shading and soil moisture for effective weed management. Seed dormancy of Q. coccinea Moench was over 1 year; best results were obtained when seeds were soaked in sulfuric acid for 15 minutes in order to break the dormancy. Germination rates of Q. coccinea Moench ranged from 69 to 73% at $25-35^{\circ}C$ and 26% at $15^{\circ}C$. The germination rates ranged from 70-84% at 2, 3, 5, 7, and 8 cm of seeding depths. In addition, the germination rates were 7% and 13% at 12 cm and 15 cm of seeding depths, respectively, and showed normal growth at the both seeding depths. Q. coccinea Moench showed a high germination rate regardless of shading levels, but shoot fresh weight varied depending on the level of shading as follows: 20%>no shading=shading 35%>shading 50%>shading 75%=shading 90%. Q. coccinea Moench did not germinate when soil had a saturation rate of either 30% or 100%. However, 60-83% of seeds germinated with optimal growth when soil had saturation rates of 60% and 80%.