• Proceedings of the Korean Society of Crop Science Conference
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• 2001.09a
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• pp.3-33
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• 2001

A review on the technical development and agricultural policy direction for sustainable agriculture has been made to clarify the present conditions of agricultural environment for food production and natural resource conservation and to study prospects and solutions successfully to achieve food safety and environment conservation as the 21st agricultural paradigm. Although great improvement of environmentally sound and resource-conserving techniques, sustainability of Korean agriculture has been damaged by quantitative reduction and quality deterioration of agricultural land resources, insufficient implementation of low-input and organic matter recycling techniques and also improper cropping system. It is concluded that goal of sustainable agriculture can be successfully achieved by further improvement of environmentally friendly techniques, and stronger escalation of national implementation programmes with more financial supports including direct payments for sustainability of agriculture under systematical support and cooperation of AKS (agricultural knowledge system).

• International Journal of Automotive Technology
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• v.2 no.4
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• pp.123-133
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• 2001

An important goal in diesel engine research is the development of a means to reduce the emission of oxides of nitrogen ($NO_x$) and soot particulate. A phenomenological model based on the multizone concept is used in the current paper to analyze and compare the effects of exhaust gas recirculation (EGR) and split fuel injection on emission from a compression-ignited, direct-injection engine. The present results show that $NO_x$ can be reduced with a minimum penalty of soot particle emission with cooled EGR. Compared with EGR, split fuel injection has a higher soot penalty at a given level of $NO_x$ reduction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.581-586
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• 2008

This study aims to examine the existing single rating index in terms of level reduction limit of heavy-weight floor impact sound. To achieve this goal, sounds which have same loudness according to rating methods were suggested to subjects. And followings are results. 1) The rating method of measurement frequency level average is more suitable than that of other methods which are dependent on specific frequency for rating heavy-weight floor impact sound. 2) Level average for measurement frequency of 31.5Hz - 500Hz is more correspondent to psycho-acoustic response than that of measurement frequency of 63Hz - 500Hz which is for KS F 2863-2, existing rating method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.617-621
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• 2007

Recent advances in automotive noise control engineering have reduced major sound sources in the vehicle, customers perceive Buzz, Squeak and Rattle (BSR) as one of important indicators of vehicle quality and durability. As the long-term goal, we expect to establish the integrated design cycle for the reduction of BSR noise in the early stage of development, which consist of design, prediction, and evaluation procedures. This is possible only with great bulk of experimental data for BSR noise. In this paper, BSR noise is experimentally identified for vehicle doors, which have been traditionally considered as one of main sources of BSR noise. Based on this result, we proposed method for the prevention of BSR noise in the vehicle doors.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.116-123
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• 2004

The demand for the stable and comfortable cabin of a high speed passenger ship is increasing. The study on shipboard comfort has been mainly concentrated on the motion control of a whole hull body. In this study, however, a new control system operated by two parallel robots (3RPS, 3SPR) such as the active suspension system of motor vehicle is proposed. The goal of this control is keeping zero velocity of the upper robot (cabin) although the lower robot (ship) is moving by the waves. Jacobian matrix was used to design the controller, From the simulation results, the remarkable reduction of motion of the cabin (upper platform) was observed. The 3SPR parallel robot shows better performance compared to the 3RPS robot.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.574-581
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• 2012

It is important to analyze the status of water quality with relation to the stream flow to attain water quality goal more effectively in the unit watersheds for the management of Total Maximum Daily Loads (TMDLs). This study developed a flow duration-water quality distribution graph to figure out water quality appearances on the flow variation and analyzed contributions of water quality observations to the impaired water bodies quantitatively by hydrologic conditions. Factors relating to water quality variation can be analyzed more precisely and assessed on the base of quantified contributions. It is considered that this approach could be utilized to establish a more effective plan for the water quality improvement including the prioritization of pollution reduction options.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.291-296
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• 2001

The computerized automation of modern manufacturing system is tremendously important for the cost reduction. Recently, the automation is being realized by Computer Integrated Manufacturing (CIM) concept and the unmanned factory is the final goal of the automation. The automation of the low level of factory is the most crucial and difficult aspect in total CIM environment since various machines are involved. A cell is defined as a manufacturing group of closely related machineries in the entire factory hierarchy, The management scheme for a cell controller is defined from the software viewpoint. The domain of a cell is designed with tasks(processes) in a multiple-task operating system. The operation of the cell is established by defining schemes for overall control of the cell domain, databases, job scheduling, communications within the domain, user-interface and communications with outside machines. Although the software is developed in a specific operating system and WINDOW facilities, the operating strategies can be applied globally.

• Korean Management Science Review
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• v.17 no.2
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• pp.115-124
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• 2000

Activity-Based Costing(ABC) is an accounting cost system which allocates the overhead cost to each cost object more accurately. ABC system achieves improved accuracy in estimating the cost of cost object by using multiple cost drivers to trace the cost of activities to the cost objects associated with the resources consumed by those activities. The selection and the aggregation of these cost driver candidates can pose difficult problems. This paper deals with these problems in mathematical programming approach. The first model is formulated as an integer programming model in cost driver selection and the second model is formulated as multi-objective goal programming model in reduction of cost drivers already selected.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.86-91
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• 2002

The regression analysis in the six sigma process is used to reduce the vibration of an electric grinder. The vibration characteristics and the contribution of each part to overall vibration of the electric grinder is investigated through various vibration measurements and frequency analysis for the assembled and disassembled one. Then the application of the regression analysis finds out that the rotating components of the armature have more severe contributions to the overall vibration than the frequency components of the fan or the gear part, which is decided with higher value of the coefficient of determination. The unbalance and looseness of the armature and the fan are tested again by the regression analysis in order to decide how much unbalance or looseness should be reduced for the predetermined goal of vibration level of the electric grinder. These results show that the regression analysis can be a valuable tool in production line to decide where and how much faults needs to be adjusted for the reduction of vibration and noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.487-490
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• 2014

These Days a lot of Noise Complaints in vicinity of Railway has been more increase than before. Almost 1/3 Residences who lives in Railway side are Exposure to Noise Pollution. Since the Apartment Buildings around Railway are getting more higher, so those of the Noise Barrier are not best solution anymore. We are going to make a New Plane with the state of the art technology for Railway Noise Abatement Control. Our Goal are focus on a development of Light Weight Noise Tunnel designed by new absorption mat'l and tunnel Stucture on the Overbridge and Viaduct of existing Railway. New Noise Tunnel will be reducing their weight more than 30% against Road Traffic One and also 10dB(A) Noise Reduction against Noise Barrier.