• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.973-976
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• 1997

Process behavior in metal cutting results from the chip formation process which is not easily observable and measurable during machining. By means of the finite element method chip formation in orthogonal metal cutting is modeled. The reciprocal interaction between mechanical and thermal loads is taken into consideration by involving the thermo-viscoplastic flow behavior of workpiece material. Local and temporal distributions of stress and temperature in the cutting zone are calculated depending on the cutting parameters. The calculated cutting forces and temperatures are compared with the experimental results obtarned from orthogonal cutting of steel AISl 4140. The model can be applied in process design for selection of appropriate tool-workpiece combination and optimum cutting conditions in term of mechanical and thermal loads.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.985-988
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• 1997

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study ,a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented in up end milling process using measured cutting forces. Size effect was identified from the analysis of specific cutting resistance obtained by using the modified undeformed chip section area.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.172-175
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• 2003

The enterprise find a solution to the problems such as a reduction of manufacturing period, accurate analysis for customer demand, improvement for customer service and rise of manufacture accomplishment. Internet is a good solution to such problems. Internet offers WWW(World Wide Web), remote control, file transfer and e-mail service. Among the services, WWW takes large portion because of convenient GUI, easy information search and unlimited information registration. Remote Monitoring Server(RMS) system that uses network service is constructed for chip mounter. Hardware base consists of RMS, chip mounter and C/S(Customer Service) server. Software includes DBMS and various modules in server home page. This provide product number, bad product number, trouble code, content and countermeasure in real-time information module, user information in setup module, detailed error information in fault diagnosis module, fault history in fault history module and customer information in customer service management module.

• Korean Journal of Computational Design and Engineering
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• v.5 no.2
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• pp.175-183
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• 2000

Proposed in this paper is a model-bated AFA (automatic feedrate-adjustment) method for maintaining smooth cutting-loads (i.e., cutting-force) during 2D-profile milling. Before the cutting-force model was established, some assumptions were verified through a series of preliminary cutting experiments (The results found that the curving-force was independent of the cutting speed and the cutting action at the cutter bosom). From the data obtained during the main cutting experiments, a “chip-load/cutting-force model”representing the cutting-force as a function of the chip-load (i.e., effective cutting-depth) and a feedrate is proposed. Based on the model. an AFA scheme for maintaining smooth cutting-force by adjusting the feedrate (i.e., F-code) according to the changes in chip-load was proposed. To check the validity of the proposed AFA scheme. another set of cutting experiments was conducted by using feedrate-adjusted NC-data while monitoring the actual machining processes using an accelerometer. The experimental results showed that the proposed AFA-scheme was quite effective.

• Proceedings of the IEEK Conference
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• 2000.11c
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• pp.153-156
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• 2000

A novel silicon retina chip based on the information processing in the vertebrate retina was designed. The chip has a novel wiring structure in which all pixels are connected through the channel of MOS transistors, which simplifies a wiring structure compared with conventional resistive networks. The proposed structure minimizes the pixel area and certainly increases a fill factor since each pixel consists of only two photodiodes and three MOS transistors. It also enables the chip to operate over a wide range of light intensity by adjusting its conductance with the gate voltage. Simulation results with SPICE showed that the chip could extract the edge of input images successfully.

• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.379-383
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• 2005

This research aims to develop DNA chip array without an indicator. We fabricated microelectrode array by photolithography technology. Several DNA probes were immobilized on an electrode. Then, indicator-free target DNA was hybridized by an electrical force and measured electrochemically. Cyclic-voltammograms (CVs) showed a difference between DNA probe and mismatched DNA in an anodic peak. Immobilization of probe DNA and hybridization of target DNA could be confirmed by fluorescent. This indicator-free DNA chip microarray resulted in the sequence-specific detection of the target DNA quantitatively ranging from $10^{-18}\;M\;to\;10^{-5}$ M in the buffer solution. This indicator-free DNA chip resulted in a sequence-specific detection of the target DNA.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.3
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• pp.165-170
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• 1992

The chip controls are investigated experimentally for the purpose of estimating cutting ability of hardened steel. In this experiment, hardened STD11 steel ($HR_c$ 60) is turned with carbide tool M20 under various cutting conditions and with several tool shapes. The main results obtained are as follows : 1) Cutting conditions of cutting speed 45m/min. feed 0.09-0.13 rev. depth of cut 0.4-0.6 are recommended for the chip excluding. 2) In case that the feed becomes larger and a lead angle of cutting tool becomes smaller, the chip excluding becomes easier. 3) It is confirmed that frank wear and crator wear on the cutting tool appear severely from about 10 min. after cutting start and chip excluding get worse.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.463-467
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• 2004

This paper presents the fabrication possibility of the micro actuator which uses a micro-thermal bubble, generated b micro-heater under pulse heating. The valve-less micropump using the diffuser/nozzle is consists of the lower plate, he middle plate, the upper plate. The lower plate includes the channel and chamber are fabricated on high processability silicon wafer by the DRIE(Deep Reactive Ion Etching) process. The middle plate includes the chamber and diaphragm d the upper plate is the micro-heater. The Micropump is fabricated by bonding process of the three layer. This paper resented the possibility of the PCR chip operation by the fabricated micropump.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.240-245
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• 2000

This paper presents the experimental study of drilling for duralumin A2024 with intermittently decelerated feed rate. It is achieved through a programmed periodic increase and decrease in the feed rate using a machining center. The following experimental result were performed with the objective of solving chip to disposal problems. In conventional drilling of aluminum, long continuous chips are produced that wind around the drill causing difficulties in eliminating chips from the cutting zone. In order to acquire the basic data necessary to regulate the chip profile, the relationship between cutting variables and chip shape was investigated. The following conclusions are established from the experimental results. At a suitable feed fluctuation ratio, intermittently decelerated feed drilling proved successful in breaking chips to appropriate lengths while maintaining stable cutting. Thus, it is an effective method for improving chip disposal. The amplitude of the dynamic component of cutting force in intermittent feed frilling is influenced by the feed fluctuation ratio.

• The Journal of Korean Medicine
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• v.25 no.1
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• pp.72-84
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• 2004

Objectives : he purpose of this study was to examine the genetic variations and changes of gene expression in the human constitutions. Methods : To analysis variations of individual gene expression, we had selected three groups of volunteers. In each group have a typical constitutional characteristics. By this rime we are analyzed their gene expression patterns by using DNA chip. Results : we can acquire a new information of standard for human constitutions. 1. The 21 genes under express and 3 genes over express in So-Yang constitution 2. The 18 genes under express and 18 genes over express in So-Eum constitution 3. The 16 genes under express and 2 genes over express in Tae-Eum constitution Conclusions : Constitution, QSCCII, Character, Genome, DNA chip.