• Journal of Environmental Policy
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• v.2 no.1
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• pp.51-75
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• 2003

The objective of this study is to analyze the problems of disposal and collection, including administrative management of agricultural PE waste and suggest effective management measurements. Information regarding problems of agricultural PE waste management were collected from field survey of farmers, regional governments and officials. On the national level, the low ratio of collection for optimal treatment of agricultural PE waste is a critical problem. , the negative discharging behavior of farmers, an illegal incineration and landfill of farmers and a lack of education and extension etc. An ambiguity of the management principle to agricultural PE waste, the differences in management among the regional governments, a lack of will of the regional governments and officials to realize SARD and lack of education and extension etc. are some of the problems in administrative management of agricultural PE waste collection. The major suggestions of this study are as follows : (1) to strengthen education and extension, (2) to adopt an improved economic incentive system and strong, lawful regulation simultaneously, (3) to use temporang collection and permanent collection site, and (4) to organize "OTC(Optimal Treatment Conference)" composed of farmers, regional cooperative, PE producers etc. for operating an effective management system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.61-61
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• 2022

For high quality bread wheat production in Korea, it is necessary to develop optimal nitrogen (N) fertilizer methods. For optimal N fertilizer, we evaluated the alteration of growth, yield, yield components and end-use qualities according to the treatment of N fertilizer amounts and timings at heading stages. Growth, yield, yield components, and end-use quality weren't altered by various timings of N fertilizer treatment conditions whereas, 1,000 grain weight and lodging degree was increased by increasing amounts of N fertilizer treatment conditions at 7 days after heading (7 DAH). Especially, lodging degree was significantly increased by 6kg/10a of N fertilizer treatment conditions at 7 DAH. The flour protein contents increased by various amounts of N fertilizer treatment conditions. However, SDS-sedimentation and bread loaf volumes were decreased by exceeding 6kg/10a of N fertilizer treatment conditions at 7 DAH. When considering the quality of bread, 6kg/10a N fertilizer treatment is best, but 3kg/10a N fertilizer treatment is more suitable for both quality and lodging at 7 DAH. Therefore, it is preferable to fertilize 3kg/10a of nitrogen at 7 DAH in addition to standard fertilizer when cultivate bread wheat.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.783-788
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• 1999

In this study, a decision support system (DSS) was developed to calculate optimal wastetreatment cost, treatment level and treatment quantity of various pollutants for applying for in rural basin. The DSS includes a gegraphic informatino system (GIS), relational database system (RDBS), water quality models(Loading function , WASP5), watershed pollution load calculation module(SPLC), optimal water quality management plan to satisfy the water quality regulations. The system can be modified by user to trace the optimal condition for decision. The effort was conducted to apply the developed DSS to select the for optimal water quality management plan small rural basin called Kwanri Stream.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.656-661
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• 2005

An optimization formulation of unconstrained damping treatment on beams is proposed to minimize vibration responses using a numerical search method. The fractional derivative model is combined with RUK's equivalent stiffness approach in order to represent nonlinearity of complex modulus of damping materials with frequency and temperature. The loss factors of partially covered unconstrained beam are calculated by the modal strain energy method. Vibration responses are calculated by using the modal superposition method, and of which design sensitivity formula with respect to damping layout is derived analytically. Plugging the sensitivity formula into optimization software, we can determine optimally damping treatment region that gives minimum forced response under a given boundary condition. A numerical example shows that the proposed method is very effective in minimizing vibration responses with unconstrained damping layer treatment.

• Proceedings of the KSLP Conference
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• 2008.03a
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• pp.28-28
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• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.349-353
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• 2004

A study on optimal placement of constrained layer damping treatment for vibration control of automotive panels is presented. The effectiveness of damping treatment depends upon design parameters such as choice of damping materials, locations and size of the treatment. This paper proposes a CAE (Computer Aided Engineering) methodology based on finite element analysis to optimize damping treatment. From the equivalent modeling technique, it is found that the best damping performance occurs as the viscoelstic patch is placed by means of the modal strain energy method of bare structural panels to identify flexible regions, which in turn facilitates optimizations of damping treatment with respect to location and size. Different configurations of partially applied damping layer treatment have been analyzed for their effectiveness in realizing maximum system damping with minimum mass of the applied damping material. Moreover, simulated frequency response function of the automotive roof with and without damping treatments are compared, which show the benefits of applying damping treatment. Finally, the optimized damping treatment configuration is validated by comparing the locations and the size of the treatment with that of an experimental modal test conducted on roof compartment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.81-82
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• 2016

The present study aims to derive optimal interface treatment conditions for emulating a monolithic construction. The joints in this construction are formed through the bonding shear evaluation method during the placement of ultra-high-performance concrete (UHPC) and normal strength concrete (NSC). The evaluation items include push-off tests for homogeneous UHPC + UHPC and heterogeneous NSC + UHPC. The experimental samples comprised a monolithic placement as the baseline, two levels for the separated placement according to the compression strength of concrete, and five levels for the interface treatment. The increase in the number of grooves and their cross-sectional areas only slightly influenced the bonding shear performance. The optimal interface treatment method for the homogeneous UHPC + UHPC construction grooves was at least 30mm. The heterogeneous NSC + UHPC construction should utilize waterjet roughening to expose the aggregate for the increased roughness.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.23-25
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• 2002

This study was conducted to understand characteristics of wastewater which is discharged from small-scale dyehouse located in Seoul downtown area and to Find the appliable treatment method on the spot. The results of this study were summarized as followings. 1. The method which is used at present is mostly flocculation by coagulant or fenton oxidation. But the treatment efficiency of them are not good. 2. The results of fenton oxidation experiment demonstrated that treatment efficiency of COD was limited, which showed the need of the additional process or the improvement of existing treatment method, while the color was reduced considerably in optimal condition. 3. The optimal condition of fenton oxidation are as followings. -Feasible pH was in the 3∼4 regardless of the kinds of iron ions, But the fluctuation of treatment efficiency with the change of pH was small - The mass ratio of H$_2$O/CODcr was used to evaluate the parameter of H$_2$O$_2$ The optimal range of this was in 0.7∼1,3 and it was observed that the ratio got higher as the quality got worse. -For iron ion, FeCl$_2$4H$_2$O turned out to be more effective for removal of color compared with was compared FeSO$_4$7H$_2$Oin. the mass ratio of Fe/H$_2$O$_2$ of 2.3∼2.8 for of FeSO$_4$7H$_2$O and 1.6∼1.8 for FeCl$_2$4H$_2$O resulted in good treatment efficiencies. 4. With adsorption process applied before fenton oxidation in order to treat the high concentration wastewater, the treatment efficiency increased by 61％ in CODcr, 55％ in color. and if the power activated carbon is injected in more than 2500mg/$\ell$, the wastewater can be treated within the effluent quality criteria.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.777-782
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• 2001

In this study, we used In-line orifice mixer for efficient chemicals mixing in water treatment. The method of using In-line orifice mixer has been already proved the improvement of water treatment efficiency. Numerical study was performed using FLUENT, a commercial code, to standard design and production of effective In-line orifice mixer. As variable for exactly standardizing, a proper ratio between an outer diameter of cone and a diameter of pipe, a distance between cone and orifice, a determination of orifice diameter for an optimal mixing, a distance between injection nozzle's position and cone, Numerical study has been performed for optimal standard and analyzed flow field on a basis of turbulent intensity in an orifice downstream.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.105-105
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• 2022

Unripen mandarin in Jeju Island is known to contain functional ingredients including various flavonoids. This Study was carried out to identify the components of Unripen mandarin extracts and Secondary metabolism by enzyme treatment on Unripen mandarin. We extracted Unripen mandarin using optimal extraction method and selected the most optimal enzyme among commercial enzymes for a Secondary metabolism. As a result, flavonoid components such as Hesperidine and Narirutin, which are known to be contained a lot in unripen mandarin, could be analyzed. However In this extraction method there were no other flavonoid components such as Nobiletin, Tangeretin known to contain in unripen mandarin. However as a result of secondary metabolism a new functional component called Prunin which was not known to be contained in unripen mandarin, was detected as a secondary metabolic product due to enzyme treatment. Through this, it can be confirmed that it would be possible to develop high-value-added products by enzyme treatment on unripen mandarin.