• The Journal of Engineering Geology
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• v.18 no.4
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• pp.381-391
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• 2008

The eigenvalue technique is introduced to overcome the problem of truncation errors caused by temporal discretization of numerical analysis. The eigenvalue technique is different from simulation in that only the space is discretized. The spatially discretized equation is diagonized and the linear dynamic system is then decoupled. The time integration can be done independently and continuously for any nodal point at any time. The results of eigenvalue technique are compared with the exact solution and FEM numerical solution. The eigenvalue technique is more efficient than the FEM to the computation time and the computer storage in the same conditions. This technique is applied to the solute transport analysis in nonuniform flow fields around underground storage caverns. This method can be very useful for time consuming simulations. So, a sensitivity analysis is carried out by using this method to analyze the safety of caverns from nearly located contaminant sources. According to the simulations, the reaching time from source to the nearest cavern may takes 50 years with longitudinal dispersivity of 50 m and transversal dispersivity of 5 m, respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.642-649
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• 2021

Energy saving standard for buildings are strengthened, the application of exterior insulation finishing system and thickness of insulation materials are increasing. Most buildings with exterior insulation finishing system is applied organic insulating material. Organic insulating material have workability, economic feasibility, reduction in construction cost, and excellent thermal insulation performance. However, Organic insulating material is very vulnerable to heat, so when a fire occurs, rapid fire spread and toxic gas are generated, causing many casualties. Inorganic insulating material can be non-combustible performance, but it is heavy and has low thermal insulation performance. Mineral wool has higher thermal insulation performance than other types of inorganic insulating material, but mineral wool is disadvantageous to workability and vulnerable to moisture. Glass bubble are highly resistant to water and chemically stable substances. In addition, the density of the glass bubble is very low and the particles are spherical, fluidity is improved by the ball bearing effect. Glass bubbles can be used with cement-based ino rganic insulating material to impro ve the weight and thermal insulatio n perfo rmance o f cement-based inorganic insulation. This study produced a inorganic insulating materials were manufactured using cement-based materials and glass bubble. In order to evaluate the insulation performance and flame retardant performance of cement-based super light-weight inorganic insulating materials using with glass bubble, insulation performance or flame retardant and non-combustible performance were evaluated after manufacturing insulating materials using micro cement and two types of glass bubbles. From the test result, Increasing the mixing ratio of glass bubbles improved the insulation performance of cement-based super light-weight inorganic insulating materials, and when the mixing ratio of glass bubbles was 10%, it sho wed sufficient flame retardant and no n-co mbustible perfo rmance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.49-57
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• 2022

The government is making great efforts to prevent crimes such as missing children by using public CCTVs. However, there is a shortage of operating manpower, weakening of concentration due to long-term concentration, and difficulty in tracking. In addition, applying real-time object search, re-identification, and tracking through a deep learning algorithm showed a phenomenon of increased parameters and insufficient memory for speed reduction due to complex network analysis. In this paper, we designed the network to improve speed and save memory through the application of Yolo v4, which can recognize real-time objects, and the application of Batch and TensorRT technology. In this thesis, based on the research on these advanced algorithms, OSNet re-ranking and K-reciprocal nearest neighbor for re-identification, Jaccard distance dissimilarity measurement algorithm for correlation, etc. are developed and used in the solution of CCTV national safety identification and tracking system. As a result, we propose a solution that can track objects by recognizing and re-identification objects in real-time within situation of a Korean public multi-CCTV environment through a set of algorithm combinations.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.317-343
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• 1977

This study was carried out to obtain the informations about evaporation from pot, soil temperature and soil atmosphere composition in pot, and the effect on the growth of nine ornamental species using seven different containers. The investigated containers were clay pot(CP), clay pot painted in green(CP-P), varnished clay pot(CP-V), polyethylene film inserting in clay pot(CP-PI), clay pot mulched with black polyethylene film(CP-PM), porcelain pot(POP), and plastic pot(PLP). Nine ornamental species were balsam(Impatiens balsamina), chrysanthemum(Chrysanthemum morifolium), cosmos(Cosmos bipinatus), English ivy(Hedera helix), geranium(Pelargonium zonale), kochia(Kochia scoparia var. trichophila), marigold(Tagetes patula), ornamental kale(Brassica oleraceae var. acephala), and salvia (Salvia splendens). The results obtained are summarized as follows: 1. Dry weight of all tested species grown in PLP, POP, CP-P, CP-V and CP-PI was heavier than that of CP. 2. Plant height in nine tested species grown in PLP, POP, CP-P, CP-V, and CP-PI was taller than that of CP. 3. Geranium grown in PLP, POP, CP-P, and CP-V gave more number of leaf than that of CP. 4. The number of flower in balsam grown in PLP, POP, CP-P, CP-V and CP-PI was more than that of CP. The result from marigold was very similar to this tendency. Spike length and floret number in salvia gave the same tendency, but its spike number was not different among containers used. 5. The average diurnal evaporation from PLP and POP was about 43% of that of CP. About two third of total evaporation from CP was through pot wall. 6. The evaporation rate from the slowest to the highest was PLP, POP, CP-P, CP-V, CP-PI, CP-PM and CP. Containers inhibiting evaporation through pot wall hold more soil moisture than CP from one day after water supply. 7. The more evaporative water-loss from containers gave the lower soil temperature. The variation of soil temperature among containers was higher during the day than the night. 8. The $O_2$ concentration of soil atmosphere in CP was higher than that of nonporous containers, and the difference between them was 0.40-1.12%. The range of the $O_2$ concentration 17.95~19.62%. The $CO_2$ concentration of soil atmosphere in CP was lower than that of nonporous containers, and its range was 0.59-1.76%. This deviation in soil atmosphere composition did not influenced on the growth of plants. 9. There was a possitive correlation between the amount of soil water and the plant growth. 10. Plant grown on CP gave more total nitrogen content in top growth than that on PLP. C/N ratio was somewhat low in plant on CP. From the above results, $O_2$ and $CO_2$ concentration in soil atmosphere did not gave enough deviation to the extent which affect the plant growth. The effect of soil moisture on the plant growth using different containers was the far-most significant factor from this investigation. Therefore, it was obious that the utilization of the nonporous container might save the cost for water supply and reduce the production cost of the pot-grown ornamental plant in Korea eventually.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.163-169
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• 2012

We have conducted three experiments to develop a fertilizer-dissolving apparatus used in fertigation or hydroponics cultivation in order to decrease the fertilizer dissolving time and labor input via automation. All of the experiments were conducted twice. In the first experiment, four selected treatments were tested to dissolve fertilizers rapidly. The first treatment was to dissolve fertilizer by spraying water with a submerged water pump, placed in the nutrient solution tank. The water was sprayed onto fertilizer, which is dissolved and filtered through the hemp cloth mounted on the upper part of the nutrient solution tank (Spray). The second treatment was to install a propeller on the bottom of the nutrient solution tank (Propeller). The third treatment was to produce a water stream with a submerged water pump, located at the bottom of the tank (Submerged). Finally, the fourth treatment was to produce an air stream through air pipes with an air compressor located at the bottom of the tank (Airflow). The Spray treatment was found to take the shortest time to dissolve fertilizer, yet it was inconvenient to implement and manage after installation. The Airflow treatment was thought to be the best method in terms of the time to dissolve, labor input, and automation. In the second experiment, Airflow treatment was investigated in more detail. In order to determine the optimal number of air pipe arms and their specification, different versions of 6- and 8-arm air pipe systems were evaluated. The apparatus with 6 arms (Arm-6) that was made of light density polyethylene was determined to be the best system, evaluated on its time to dissolve fertilizer, easiness to use regardless of the lid size of the tank, and easiness to produce and install. In the third experiment, the Submerged and Arm-6 treatments were compared for their dissolving time and economics. Arm-6 treatment decreased the dissolving time by 8 times and proved to be very economic. In addition, dissolving characteristics were investigated for $KNO_3$, $Ca(NO_3)_2{\cdot}4H_2O$, and Fe-EDTA.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.11
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• pp.947-956
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• 2009

Residual petroleum hydrocarbons after an oil spill may accumulate in the marine benthic ecosystem due to their high hydrophobicity. A lot of monitoring data are required for the estimation of ecosystem exposure to residual petrochemicals in an ecological risk assessment in the affected region. To save time and cost, the environmental exposure to them in the affected ecosystem can also be assessed using a simple food-web bioaccumulation model. In this study, we evaluated residual concentrations of four selected polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, and benzo[a]pyrene) in a hypothetic benthic ecosystem composed of six species under two exposure scenarios. Body-residue concentration ranged 5~250 mg/kg body depending on trophic positions in an extreme scenario in which the aqueous concentrations of PAHs were assumed to be one-tenth of their aqueous solubility. In addition, bioconcentration factors (BCFs) and bioaccumulation factors (BAFs) were evaluated for model species. The logarithm of bioconcentration factor (log BCF) linearly increased with increasing the logarithm of 1-octanol-water partition coefficient (log $K_{OW}$) until log $K_{OW}$ of 7.0, followed by a gradual decrease with further increase in log $K_{OW}$ without metabolic degradation. Biomagnification became significant when log $K_{OW}$ of a pollutant exceeded 5.0 in the model ecosystem, indicating that investigation of food-web structure should be critical to predict biomagnifications in the affected ecosystem because log $K_{OW}$ values of many petrochemicals are higher than 5.0. Although further research is required for better site-specific evaluation of exposure, the model simulation can be used to estimate the level of the ecosystem exposure to residual oil contaminants at the screening level.

• Korean Journal of Organic Agriculture
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• v.13 no.3
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• pp.315-332
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• 2005

This study was conducted to assess the nutritional value and the safety of the fermented food wastes (FFW) made by adding lactobacillus spp. and bacillus spp. at the ratio of 3:7, respectively to food wastes collected everywhere, and also to determine effects on the performances, carcass characteristics and economical profitability when FFW was fed to pigs. For swine trial, FFW was formulate to pellet by utilizing different feed ingredients, and its formulated FFW pellet was used in this feeding trial. Treatments were consisted of different ratios (T1: $100+0\%$, T2: $75+25\%$, T3: $50+50\%$, T4: $25+75\%$, T5: $0+100\%$) of FFW pellet to commercial diet. A total of 20 male pigs were allotted to treatments of five groups of four pigs per pen. Experimental period lasted for 4 months. The nutritional composition of FFW was 56.7, 19.5 and $19.5\%$ for moisture, crude protein and ether extract, respectively. Salt content was $0.39\%$. Noxious microorganisms such as salmonella and E. coli were not detected in FFW, and contents of heavy metal and aflatoxin B1 were lower than the standard. Nutritional values of FFW pellet satisfied over $100\%$ of requirements presented in official Korean feeding standard for swine. Feeding trial for pigs showed that feed intakes were significantly (P<0.05) decreased with increasing levels of FFW pellet. T2 treatment was ideal ratio under the consideration of economical value of feeds and body weight gain of pigs. For carcass characteristics, dressing rate ($\%$) was highest in T3, and carcass grades for T2, T3 and T4 treatments were estimated as 'A'. Feed cost for FFW per kg was ${\won}167.95$, which implies $52\%$ of commercial feed cost (${\won}350/kg$). Thus, this result implied the decreased feed cost in the swine farm. Conclusively, the utilization of food wastes as feed source may lead to the reduced environmental pollution and the practice of organic livestock farming. However, our results showed that excessive amount of fermented food wastes supplementation to pigs might give rise to their reduced palatability and delayed growth.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.8
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• pp.367-376
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• 2007

In this paper, we introduce an application-specific and adaptive power management technique for portable systems that support dynamic voltage scaling (DVS). We exploit both the idle time of multitasking systems running soft real-time tasks as well as memory- or CPU-bound code regions. Detailed power and execution time profiles guide an adaptive power manager (APM) that is linked to the operating system. A post-pass optimizer marks candidate regions for DVS by inserting calls to the APM. At runtime, the APM monitors the CPU's performance counters to dynamically determine the affinity of the each marked region. for each region, the APM computes the optimal voltage and frequency setting in terms of energy consumption and switches the CPU to that setting during the execution of the region. Idle time is exploited by monitoring system idle time and switching to the energy-wise most economical setting without prolonging execution. We show that our method is most effective for periodic workloads such as video or audio decoding. We have implemented our method in a multitasking operating system (Microsoft Windows CE) running on an Intel XScale-processor. We achieved up to 9% of total system power savings over the standard power management policy that puts the CPU in a low Power mode during idle periods.

• Journal of Korea Spatial Information System Society
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• v.5 no.1 s.9
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• pp.49-63
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• 2003

Recently, two international standard organizations, ISO and OGC, have done the work of standardization for GIS. Current standardization work for providing interoperability among GIS DB focuses on the design of open interfaces. But, this work has not considered procedures and methods for designing GIS DB. Eventually, GIS DB has its own model. When we share the data by open interface among heterogeneous GIS DB, differences between models result in the loss of information. Our aim in this paper is to revise the design guidelines for geographic information databases in order to make consistent spatial data models, logical structures, and semantic structure of populated geographical databases. In details, we propose standard guidelines which convert ISO abstract schema into relation model, object-relation model, object-centered model, and geometry-centered model. Furthermore, we provide sample models for applying these guidelines in commercial GIS S/Ws. Building GIS DB based on design guidelines proposed in the paper has the following advantages: the interoperability among databases, the standardization of schema definitions, and the catalogue of GIS databases through.

• Journal of the Korean Society of Food Science and Nutrition
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• v.2 no.1
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• pp.73-80
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• 1973

1. Generally speaking, our people have been carrying out the government policy of using grains other than rice comparatively well. But it is desirable that the government heirs the whole nation as well as the farmers to understand better the scientific meaning of using foods made from the flour of various grains. This will greatly improve the nation's eating habits, for it will make people discard the habit of eating only boiled-rice, which will not only improve our national health but will also increase the national income. 2. For the purpose of improving health and developing intellectual faculties of our mind, we had better, if possible, get much protein from plants(especially beans) which we can obtain more readily than from animals. However if we must use animal protein, we should dependonly on livestock. Pregnant women and new-born children must not be in ill health because of malnutrition caused by following groundless superstitions about foods: for example, some religions forbid the use very healthful foods or some traditional conventions do the blend of certain foods together with other victuals. 3. It is good that we conquer the difficulty of living in the season of spring poverty by having other substitute for regular victuals. But it requires us to pay a careful attention to the food and to do research on many foods problems such as food pollution. Farmers should cooperate with each other and help those who have very little arable land, or even those who have no place for cultivating, to grow miscellaneous cereals on the land which other farmers don't use that year. 4. On the whole, farmers have a good appetite for any, food, whatever it is. Neverthless, because they aren't econmically well-off, they generally eat hot meals only for breakfast and supper in the busy faming season. They eat a tepid lunch which, they think saves time and cooking fuel. In conclution, I feel sorry that many village farmers still steeped in conventional thought and superstition are inclined to have an unbalanced diet of boiled-rice and that they continue not to use the floor from other grains all the year round. when these unscientific dieting customs mentioned above are discarded, we will be able to enjoy good health, better knowledge or intellegence, and higher income. Then we will ba able to make our present lives more self-reliant and self-supporting.