• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.182-186
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• 2007

This paper studied performance characteristics of hybrid automotive to replace existing fossil fuel vehicles. Specially, about power split type HEV that is T-HEV's drive system when a vehicle drives at steady speed, monitored both output of each engine, motor and generator and battery SOC (state of charge) and analyzed performance characteristic of power transmission system and electricity power parts. This study shows those that acquired and analyzed information from signals between HCU and each controller of actual T- vehicle. From this study, it is confirmed that each conditions of EV and HEV drive can be a improvement with respect to the fuel efficiency of vehicles.

• Macromolecular Research
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• v.13 no.2
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• pp.102-106
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• 2005

Poly(methyl methacrylate) (PMMA)/sodium montmorillonite (Na-MMT) nanocomposites were prepared with a novel method utilizing a macroazoinitiator (MAI). To induce the intergallery polymerization of methyl methacrylate (MMA), the MAI containing a po1y(ethylene glycol) (PEG) segment was intercalated between the lamellae of Na-MMT and swelled with water to enhance the diffusion of MMA into the gallery. The structure of the nanocomposite was examined using X-ray diffraction and transmission electron microscopy, and the thermal properties were examined using differential scanning calorimetry and thermogravimetry. The PMMA/Na-MMT nanocomposite prepared by intergallery polymerization showed a distinct enhancement of its thermal properties; an approximately $30^{\circ}C$ increase in its glass transition temperature and an $80\sim100^{\circ}C$ increase in its thermal decomposition temperature for a $10\%$ weight loss.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.331-333
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• 2005

In this paper, we implemented the monitoring and control of geothermal heating and cooling system using mobile devices. The main idea of this system is to provide the convenience if the system can be controled in remote place with monitoring using the mobile devices like PDA. Basically, the system consists of the Server-Client structure divided into two parts, one is PDA and PC, the other is PC and PLC(Programmable Logic Controller). The PDA, which is equipped with Windows CE as as, monitors the status of the devices (motors and sensors, etc) attached to PLC and controls them. This does the system to be controled by the commands, which we assume to control, with wireless transmission between PC and PLC. The PDA parts are responsible for monitoring and control the devices connected to the PLC, and the PC part which equipped with the application is to provide the relation between PDA and PLC. The Ladder Program is used to control the sequences of the PLC..

• Transactions of Materials Processing
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• v.14 no.3 s.75
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• pp.207-214
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• 2005

Blanking process is widely used fur producing various structural parts. However, fine blanking technology is frequently used as a single step blanking operation with clean cut surface of a sheared surface because the fractured surface of parts causes serious problems in the final product and therefore it must be removed by the post-processing in case of the conventional blanking. In the present investigation, a fine blanking process was designed within the framework of progressive die to produce a carrier plate assembled within the auto transmission. Finite element analysis of the shearing behavior at the respective stage of the progressive fine blanking was conducted to validate the designed die parameters. Finally the designed progressive fine blanking process was experimentally evaluated by using the machined die.

• The Journal of Information Technology
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• v.9 no.1
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• pp.9-19
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• 2006

Medications or conitive-behavior methods have been mainly used as a treatment of alcoholism. lately the virtualy technology has been applied to the kink of alcoholic disorders. A virtual environment makes him having avility to over come the drink. In this study, we were implemented by making panorama images and 3D object modules using 3D MAX, VRML, JAVA. And the BAR stimulator that composed with a position sensor, head mount display, and audio system, is suggested. To illustrate the physiological difference between a person who has a alcoholism and without a liquor bottle, heart rate was measured during experiment, and also measured a person's HR after the virtual reality training. The system measures the Physiological signals such as ECG, Temperature, analyzes those data automatically. The system has two parts, one is physiological data acquisition part which gets the body signal, and the other one is mobile nuit which includes signal processing and transmission functions, And Bluetooth allows two parts to communicate with each other. we demonstrated the subjective effectiveness of virtual reality psychotherapy through the clinical experiment.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.154-164
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• 2011

This study was conducted to develop the semi-crawler type mini-forwarder that can be operated comfortable small-scale logging operation in the steep terrain and also used at a variety of operations such as the civil work in erosion control and forest-road. Considering the minimum turning radius and the width of forest operation road, the total length, width and loading capacity of the semi-crawler type mini-forwarder is 5,750 mm, 1,900 mm and $2.5m^{3}$, respectively. The maximum engine power is 96ps at 3600 rpm. Selected hydraulic pumps are consists of two main pumps and two sub-main pumps. Main hydraulic pumps are utilized to running motor of the front wheel and rear crawler. Sub-main pumps are utilized to the actuation parts such as steering, crane, out-rigger and dump cylinder. The transmission was adapted as the HST (Hydro-Static Transmission) system. The driving parts are designed and manufactured as the front wheel type and the rear crawler type. The steering type was manufactured as the ackerman type. Driving control parts type was designed and manufactured as driver's seat type of normal cars. It is also attached on auxiliary equipments such as winch, log grapple and out-rigger. The traveling speed of the semi-crawler type mini-forwarder in forest road was 5.3 km/hr to 7.7 km/hr.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.189.2-189.2
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• 2010

The purpose of this study is fatigue damage assessment for large sized casting parts (hub and mainframe) of the 3MW offshore wind turbine by computer simulation. Hub and mainframe durability assessment is necessary because wind turbine have to guarantee for 20 years. Fatigue life evaluation must be considered all of fatigue load conditions as the components are wind load transmission path. Palmgren-Miner linear damage accumulation hypothesis is applied for fatigue life estimation with stress-life approach. S-N curve for the spheroid graphite cast iron EN-GJS-400-18-LT is derived according to durability guidelines. Reduction factors were applied for survival probability, surface roughness, material quality and partial safety factor according to Germanischer Lloyd rules. To calculate fatigue damage, stress tensors, extracted from the unity load calculation from ANSYS is multiplied with time track of fatigue loads extracted from GH bladed. Damage accumulation is performed with all of fatigue load conditions at each finite element nodes. In this study maximum nodal damage value is under 1.0. casted parts are safe. This research was financially supported by the Ministry of Knowledge Economy(MKE), Korea Institute for Advancement of Technology(KIAT) and Honam Leading Industry Office through the Leading Industry Development for Economic Region.

• IE interfaces
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• v.17 no.4
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• pp.482-489
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• 2004

As the functional characteristics of passenger cars have reached to a satisfactory level, customers place more concerns with the aesthetic aspects of interior designs. The present study developed satisfaction models of passenger car interior materials for six parts including crash pad, steering wheel, transmission gearshift knob, audio panel, metal grain, and wooden grain. Eight to fifteen material design variables such as color, embossing, and smoothness were defined for the six interior parts based on literature survey, customer reviews, and expert opinions. A satisfaction survey was conducted for 30 vehicles with 30 participants ($mean{\pm}SD$ of age = $28.7{\pm}6.6$) by using a modified magnitude estimation scale. Based on the survey results, the material design variables were screened from statistical, technical, and practical aspects. With the screened variables, satisfaction models were developed by using the quantification I method for the six interior parts, indicating the importance of material design variables and preferred material properties.

• Journal of Communications and Networks
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• v.4 no.4
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• pp.336-343
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• 2002

A major challenge for next generation mobile communication is capturing the system architecture’s complexity with all its internal and external dependencies. Seamless integration of heterogeneous environments in all system parts is a key requirement. Moreover, future systems have to consider the different evolution cycles of individual system parts. Among those, services are expected to change the fastest. With respect to these considerations, we propose an overall architecture for next generation mobile communication systems. It covers all system parts from wireless transmission to applications including network and middleware platform. Our approach focuses on adaptability in terms of recon- figurability and programmability to support unanticipated system evolution. Therefore, we consider abstraction layers which consist of adaptable cooperating components grouped by open platforms rather than rigid system layers. In addition to that, we introduce cross-layer cooperation allowing an efficient use of the available resources. Specific scenarios illustrate the feasibility of our approach.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.508-513
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• 2006

Anchor bolt in baseplate fastenings on the slab track is an important component to conform placing and safety of fastenings. Due to the way of load transmission control of fastenings, sometimes anchor bolt has to be applied lateral load. So we have to take care for it when we design. Especially, in the case of anchor bolt which is applied loads repeatedly, we have to consider fatigue failure. If parts of machine are damaged in static loads, stress will exceed the yield strength. So parts could be transformed largely. Therefore because they are visible to the naked eyes, we can replace parts before failure. However, because fatigue failure that are invisible to the naked eyes happen unexpectedly, it's very dangerous. To make a reasonable design of anchor bolts, we will analyze them by changing diameters of anchor bolt, quality of insert, initial gap between anchor bolt and insert, the presence of insert, etc. which affect the stresses of anchor bolts. We can get the maximum and minimum amplitude of stress through the modified Goodman diagram or Smith diagram which represents limit of all strengths and stress components to the average stress. We also tried to show the way of examining the expected th life of anchor bolt briefly through considering above.