• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1779-1786
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• 2000

Most of traditional design processes of mechanical parts are regarded as sequential and discrete, since different kinds of softwas should be introduced. In this paper, we develop an integrated fram ework for virtual design and performance testing of an automobile seat. The system is composed of four modules, i.e. CAD, static analysis, dynamic analysis, and draft drawing module. In the CAD module, PRO/ENGINEER 3D seat model is created using parameters to be modified with the result of static and dynamic analysis. In the static analysis, headrest tere used in each design stage make it difficult to feedback their results to upstream process. These discrete processes may result in time loss and cost rise. In recent years, life cycle of product is reduced. To have competence with others, new concept design processt is simulated using ANSYS. In the dynamic analysis module, FMVSS201 test is simulated using DADS. Overall data flow is controlled by Motif. The advantage of the system is that even a novice can perform and review the whole design process, without a good hand at professional design/analysis S/W in each stage. The system also provides a virtual design space, where engineers in different development stage can access common data of design models. The concept could be applied to other fields and it could reduce time and money required in design process.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.1-6
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• 2010

This study presents the practical design modification to improve the retracting performance of the pyro-typed high power pretensioner. 3 components of the pretensioner are redesigned and the usefulness of the design modification is verified by the experiment. During the pretensioning process, the gas blast generated from the gunpowder is transferred to the rack-pinion gear through the manifold. The rack-pinion gear is connected with the spool where the webbing is rolled up. According to the rotation of the pinion, the spool is turned and the webbing is winded. To help the gas blast flow well, the shape of the inner cross section of the manifold is changed. The spur gear design program is developed and used to find the best combination of the rack-pinion gear pair to increase the power transmission efficiency. The pinion guide is installed on the spool to prevent the vibration of the pinion. As a result of the experiment, the amount of the web retraction length is increased when every single design modification is applied. Therefore, the retracting performance of the pretensioner is considered to be improved if the presented design modifications are applied.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.465-465
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• 2009

Wind power is one of the most reliable renewable energy sources and the installed wind turbine capacities are increasing radically every year. Although wind power has been favored by the public in general, the problem with the impact of wind turbine noise on people living in the vicinity of the turbines has been increased. Low noise wind turbine design is becoming more important as noise is spreading more adverse effect of wind turbine to public. This paper demonstrates the design of 10 kW class wind turbines, each of three blades, a rotor diameter 6.4m, a rated rotating speed 200 rpm and a rated wind speed 10 m/s. The optimized airfoil is dedicated for the 75% spanwise position because the dominant source of a wind turbine blade has been known as trailing edge noise from the outer 25% of the blade. Numerical computations are performed for incompressible flow and for Mach number at 0.145 and for Reynolds numbers at $1.02{\times}10^6$ with a lift performance, which is resistant to surface contamination and turbulence intensity. The objective in the low design process is to reduce noise emission, while sustaining high aerodynamic efficiency. Dominant broadband noise sources are predicted by semi-empirical formulas composed of the groundwork by Brooks et al. and Lowson associated with typical wind turbine operation conditions. During the airfoil redesign process, the aerodynamic performance is analyzed to minimize the wind turbine power loss. The results obtained from the design process show that the design method is capable of designing airfoils with reduced noise using a commercial 10 kW class wind turbine blade airfoil as a basis. The new optimized airfoil clearly indicates reduction of total SPL about 3 dB and higher aerodynamic performance.

• Fire Science and Engineering
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• v.28 no.6
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• pp.22-27
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• 2014

In this study a Fuel bed where surface fire spreads through is made to measure the data such as the flame height, radiation, spread rate and temperature distribution of Fuel bed. As experimental variables species of trees, wind velocities and slop are chosen. Fallen leaves of Quercus Variabilis (Q.V.) and Pinus Densiflora (P.D.) are used as fuel. Wind velocity is controlled by simply designed wind turnnel from 1 to 5 m/s. Slope of fuel bed is changed from $0^{\circ}$ to $30^{\circ}$. For the measurements of temperature distribution and spread rate total 35 of K-type 1.6 mm thermocouples are positioned as a lattice design. Radiant heat flow meters are used besides video camera and thermovision camera.

• Journal of Korea Water Resources Association
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• v.33 no.3
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• pp.341-350
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• 2000

The objectives of this study are to develop a state-space form of stochastic dynamic storage function routing model and to test the model performance for real-time flow forecast. The selected study area is the main Han River starting from Paldang Dam site to Indogyo station and the 13 flood events occurred from 1987 to 1998 are selected for computing model parameters and testing the model performance. It was shown that the optimal model parameters are quite different depending on Hood events, but the values used on field work also give reasonable results in this study area. It is also obvious that the model performance from the stochastic-dynamic model developed in this study gives more accurate and reliable results than that from the existing deterministic model. Analysis for allowable forecast lead time leads that under the current time step the reasonable predicted downstream flows in 5 hours time advance are obtained from the stochastic dynamic model on relatively less lateral inflow event in the study area.

• Journal of Pharmaceutical Investigation
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• v.22 no.3
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• pp.197-204
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• 1992

A gas chromatographic method using nitrogen phosphorous selective detection was developed for simultaneous determination of haloperidol and its metabolite, reduced haloperidol, in human plasma. Combelen was used as internal standard, The method involved extraction and trimethylsilylation followed by the injection of $2-4\;{\mu}l$ of benzene layer, which was used to dissolve the trimethylsilylated derivatives of haloperidol and reduced haloperidol, onto SE-54 column [5% phenyl methyl silica fused capillary column, $16m{\times}0.22\;mm$ $(I.D.){\times}0.33\;{\mu}m$ (coated thickness)]. The temperature of column oven was programmed from $200^{\circ}C\;to\;300^{\circ}C$ at the increase rate of $10^{\circ}C/min and also the temperatures of injector and detector were set at $300^{\circ}C$. Helium was used as carrier gas and its flow rate was maintained at 30 ml/min. The detection was conducted with nitrogen phosphorous selective detector. The retention times for combelen, reduced haloperidol and haloperidol were found to be 9.14, 9.75 and 9.99 min, respectively. The detection limits for haloperidol and reduced haloperidol in human plasma were both 0.2 ng/ml. The coefficients of variation of the intra-assay were generally low (below 9.8%). The mean absolute recoveries of added haloperidol and reduced haloperidol from plasma were 72% and 84%, respectively. No interferences from endogenous substances were found.

• Applied Chemistry for Engineering
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• v.24 no.1
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• pp.104-111
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• 2013

Poymer blends of two degradable aliphatic polyesters, relatively expensive material polylactic acid (PLA) and relatively inexpensive material poly(butylene adipate-co-terephthalate) (PBAT), were used in this study. Three different kinds of modifiers were used with various amounts. Diisocyanate type methylenediphenyl 4,4'-diisocyanate (MDI) and hexamethylene diisocyanate (HDI) were used as modifiers and epoxy type coupling agents also used. The melt flow index (MFI) and dynamic viscoelasticity of various compositions of PLA/PBAT blends were studied. The mechanical property and morphology with respect to the fracture surface of PLA/PBAT blends were also investigated using tensile test and field emission scanning electronic microscopy, respectively. These tests were also used to verify the compatibility of PLA/PBAT and the effect of mechanical properties due to the use of modifiers. Tensile properties of PLA/PBAT blends modified with HDI were improved remarkably.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.105-113
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• 2009

The performance of a direct-injection type diesel engine often depends on the strength of swirl or squish, shape of combustion chamber, the number of nozzle holes, etc. This is of course because the combustion in the cylinder was affected by the mixture formation process. In this paper, combustion process of biodiesel fuel was studied by employing the piston which has several grooves with inclined plane on the piston crown to generate swirl during the compression stroke in the cylinder in order to improve the atomization of high viscosity fuel such as biodiesel fuel and toroidal type piston generally used in high speed diesel engine. To take a photograph of flame, single cylinder, four stroke diesel engine was remodeled into two stroke visible engine and high speed video camera was used. The results obtained are summarized as follows; (1) In the case of toroidal piston, when biodiesel fuel was supplied to plunger type injection system which has very low injection pressure as compared with common-rail injection system, the flame propagation speed was slowed and the maximum combustion pressure became lower. These phenomena became further aggravated as the fuel viscosity gets higher. (2) In the case of swirl groove piston, early stage of combustion such as rapid ignition timing and flame propagation was activated by intensifying the air flow in the cylinder. (3) Combustion process of biodiesel fuel was improved by the reason mentioned in paragraph (2) above. Consequently, the swirl grooves would also function to improve the combustion of high viscosity fuel.

• Korean journal of food and cookery science
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• v.8 no.2
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• pp.137-145
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• 1992

A computer-assisted microbiological quality assurance program was developed based on HACCP data obtained from a 500 bed general hospital by assessing time and temperature conditions and microbiological qualities of six categories of menu items according to the process of food product flow. The purpose of the study was to develop a computer-assisted microbiological quality assurance program in order to simplify the assessment procedures and to provide a maximum assurance to foodservice personnel and the public. A 16-Bit personnel computer compatible with IBM-PC/AT was used. The data base files and processing programs were created using dBASE III plus packages. The contents of the computerized system are summarized as knows: 1. When the input program for hazard analysis runs, a series of questions are asked to determine hazards and assess their severity and risks. Critical control points and monitoring methods for CCPs are identified and saved in Master file. 2. Output and search programs for hazard analysis are composed of 6 categories of recipe data file list, code identification list, and HACCP identification of the specific menu item. 3. When the user selects a specific category of recipe from 6 categories presented on the screen and runs data file list, a series of menu item list, CCP list, monitoring methods list are generated. When the code search program runs, menu names, ingredients, amounts and a series of codes are generated. 4. When the user types in a menu item and an identification code, critical control points and monitoring methods are generated for each menu item.

• Journal of KIBIM
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• v.1 no.1
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• pp.6-12
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• 2011

BIM(Building Information Modeling) technologies are the most effective for the maintenance of infrastructures because they provide information sharing througout the life-cycle of structures and support close communication between different project stages. Systematic and well-organized data play a fundamental role for the effective maintenance of subway tunnel. In this paper, 3D information models for maintenance of BIM-based subway tunnel structures are developed. Standard classifications for the maintenance and construction information classification system were adopted. A classification system based on construction information classification system was built considering procedures of maintenance work. It provides optimization and standardization of the work flow for the maintenance of subway structures by applying information modeling processes instead of the current maintenance practices. It can effectively reduces the life cycle cost and time for the maintenance. The proposed system can be utilized for the maintenance history management to enhance current maintenance system.