• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.164-169
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• 2006

We have developed the spirometer system; many patients having weak respiration have difficulties in using conventional spirometers in hospitals, because their weak breath can be affected by the errors of inertia and instrumental pressure. We have developed a new ultrasound spirometer using an ARM 920T processor. To detect weak respiratory signals, we add a comparator circuit, which can afford more information of respiration characteristics such as respiration volume, directions, and velocities. We have also developed Gill for graphical display of respiration characteristics. Through the pilot test, it has been verified that the developed spirometer is operating reliably.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.11a
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• pp.3-14
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• 2005

We Investigated minutely how the biosorption technology using algal biomass is opened in Canadian technology society. Making comparative study for relative technologies in views of overall unit operation cost, we could grasp next facts. - Algal biomass plays the competitive performance for various metals. - Algal biomass biosorbent is regenerated. - Reactor system is not and involved one. This means that algal biomass occupies the strong position as biosorbent. Especially, in North America, for the purpose of metal bearing wastewater treatment, 20 hundred million US dollars was appropriated a sum for the purchase of ion exchange resin. But it is only thirty million US dollars if algal biomass biosorbent is used on behalf of ion exchange resin. Furthermore, the expenses for same treatment can be cut down additively through metal recovery.

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.23-25
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• 1994

A simple analytical method that allows direct monitoring of small amount of CO$_2$ in a CO$_2$ discharge tube which utilizes the optoacoustic detection technique is described. The dependence of the optoacoustic signal on the mole fraction of CO$_2$ was shown that the system responded linearly to the amount of CO$_2$ present in the miniature discharge cavity equipped with Cu electrodes. It was also found that fraction of dissociated CO$_2$ varied from 14 to 37% of the initial concentration which depended on the current and the pressure in the tube. This simple and easy detection method has proven to possess the practical advantages over the conventional systems for the study of CO$_2$ laser electrodes.

• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.3
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• pp.610-625
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• 2015

In this paper the wave run-up around a circular column in regular waves is numerically calculated to investigate the applicability of the Modified Marker-Density (MMD) method to prediction of wave run-up around an offshore platform. The MMD method is one of the methods to define the highly nonlinear free surface. The governing equations are the Navier-Stokes equations and the continuity equation which are computed in Cartesian grid system. To validate incident waves generated by numerical simulation, those are compared with the solutions of the Stokes $5^{th}$ order wave theory. The wave run-up simulations are performed varying the steepness and period of incident waves as referred experimental data. The numerical results are compared to the experimental data and the results show good agreements.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.73-78
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• 2003

In this research, we implement Realtime Air Diffusion Prediction System which is a parallel Fortran model running on distributed-memory parallel computers. The system is designed for air diffusion simulations with four-dimensional data assimilation. For regional air quality forecasting a series of dynamic downscaling technique is adopted using the NCAR/Penn. State MM5 model which is an atmospheric model. The realtime initial data have been provided daily from the KMA (Korean Meteorological Administration) global spectral model output. It takes huge resources of computation to get 24 hour air quality forecast with this four step dynamic downscaling (27km, 9km, 3km, and lkm). Parallel implementation of the realtime system is imperative to achieve increased throughput since the realtime system have to be performed which correct timing behavior and the sequential code requires a large amount of CPU time for typical simulations. The parallel system uses MPI (Message Passing Interface), a standard library to support high-level routines for message passing. We validate the parallel model by comparing it with the sequential model. For realtime running, we implement a cluster computer which is a distributed-memory parallel computer that links high-performance PCs with high-speed interconnection networks. We use 32 2-CPU nodes and a Myrinet network for the cluster. Since cluster computers more cost effective than conventional distributed parallel computers, we can build a dedicated realtime computer. The system also includes web based Gill (Graphic User Interface) for convenient system management and performance monitoring so that end-users can restart the system easily when the system faults. Performance of the parallel model is analyzed by comparing its execution time with the sequential model, and by calculating communication overhead and load imbalance, which are common problems in parallel processing. Performance analysis is carried out on our cluster which has 32 2-CPU nodes.

• Journal of Internet Computing and Services
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• v.7 no.3
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• pp.119-132
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• 2006

The network based security techniques well-known until now have week points to be passive in attacks and susceptible to roundabout attacks so that the misuse detection based intrusion prevention system which enables positive correspondence to the attacks of inline mode are used widely. But because the Misuse detection based Intrusion prevention system is proportional to the detection rules, it causes excessive false alarm and is linked to wrong correspondence which prevents the regular network flow and is insufficient to detect transformed attacks, This study suggests an Intrusion prevention system which uses Support Vector machines(hereinafter referred to as SVM) as one of rule based Intrusion prevention system and Anomaly System in order to supplement these problems, When this compared with existing intrusion prevention system, show performance result that improve about 20% and could through intrusion prevention system that propose false positive minimize and know that can detect effectively about new variant attack.

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.31-37
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• 2010

In this paper, a photovoltaic system is designed with PWM(Pulse Width Modulation) voltage source inverter. Proposed synchronous signal and control signal was processed by 56F8323 microprocessor for stable modulation. The PWM voltage source inverter using inverter consists of complex type of electric power converter to compensate for the defect, that is solar cell cannot be developed continuously by connecting with the source of electric power for ordinary use. It can cause the effect of saving electric power, from 10 to 20[%]. The PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. In addition, I connected extra power to the system through operation the system voltage and inverter power in a synchronized way by extracting the system voltage so that the phase of the system and PWM voltage inverter can be synchronized. In the system of this research showed good results after being controlled in order to provide stable power to the load and the system through maintaining and low output power of harmonics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.132-139
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• 2008

The blade vibration problem of bladed disk is the most critical subject to consider since it directly affects the stable performance of the engine as well as life of the engine. Especially, due to complicated vibration pattern of the bladed disk, more effort was required for vibration analysis and test. The research of measuring the vibration of the bladed disk, using NSMS(Non-intrusive stress measurement) instead of Aeromechanics testing method requiring slip ring or telemetry system with strain gauge, was successful. These testing can report the actual stresses seen on the blades; detect synchronous resonances that are the source of high cycle fatigue (HCF) in blades; measure individual blade mis-tuning and coupled resonances in bladed disks. In order to minimize the error being created due to heat expansion, the tip timing sensor is installed parallel to the blade trailing edge, yielding optimal result. Also, when working on finite element analysis, the whole bladed disk has gone through three-dimensional analysis, evaluating the family mode. The result of the analysis matched well with the test result.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.291-297
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• 1998

Cop protein has been overexpressed in Escherichia coli using a T7 RNA polymerase system. Purification to apparent homogeneity was achieved by the sequential chromatography on ion exchange, affinity chromatography, and reverse phase high performance liquid chromatography system. The molecular weight of the purified Cop was estimated as 6.1 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). But the molecular mass of the native state Cop was shown to be 19 kDa by an analytical high performance size exclusion chromatography, suggesting a trimer-like structure in 50 mM Tris-HCI buffer (pH 7.5) containing 100 mM NaCl. Cop protein Was calculated to contain $39.1% {\alpha}-helix, 16.8% {\beta}-sheet$, 17.4% turn, and 26.8% random structure. The DNA binding property of Cop protein expressed in E. coli Was preserved during the expression and purification process. The isoelectric point of Cop was determined to be 9.0. The results of amino acid composition analysis and N-terminal amino acid sequencing of Cop showed that it has the same amino acid composition and N-terminal amino acid sequence as those deduced from its DNA sequence analysis, except for the partial removal of N-terminal methionine residue by methionyl-aminopeptidase in E. coli.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.1
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• pp.30-38
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• 2014

Hydro-acoustic survey was carried out to investigate the spatial characteristics of fish distribution near two artificial reefs (AO: large octagonal semi-sphere and AC: combined custom built) having different types in Jeju marine ranching area. The survey system consisted of scientific echo sounder (EK60), DGPS system, and ECDIS (Mecys). Field survey was conducted on August and October 2012 with star survey and line transect survey line method, and species composition was investigated from gill net fishing survey. The acoustic signals from individual fishes and small fish schools were mainly recorded around AO, but large and strong signals from large fish school were mainly detected in the top layer of and the water column near AC. The echogram suggest that the fish aggregation for the two types of AO and AC exist the significant difference in fish species and spatial distribution pattern.