• Journal of Biomedical Engineering Research
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• v.36 no.4
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• pp.103-108
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• 2015

Discrimination of Parkinson's disease (PD) from Essential tremor (ET) is often misdiagnosed in clinical practice. Since tremor is time-varying signal, and dominant and harmonic frequencies are shown in tremor only with moderate or severe symptom, there are some limitations to use frequency related features. Moreover, patients with PD or ET can suffer from both resting tremor and postural tremor. In this study, 28 patients with PD and 17 patients with ET were enrolled. Tremor was measured with accelerations on the more affected hand during resting and postural conditions. The ratio of root mean square (RMS) of resting tremor to RMS of postural tremor, the mean coefficients of autocorrelation function (ACF), and the mean of differences of two adjacent coefficients of ACF at resting and postural were calculated and compared between PD and ET. The performance showed 98% accuracy with support vector machine and leave-one-out cross validation. In addition, the method accurately differentiated the patients with tremor-dominant PD from patients with ET, with 100% accuracy. Therefore, the developed algorithm can assist clinicians in diagnosing and categorizing patients with tremor, especially, patients with mild symptom or the early stage of a disease, for proper treatment.

• Archives of Plastic Surgery
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• v.34 no.3
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• pp.409-412
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• 2007

Purpose: Percutaneous Kirschner wire fixation is common method for hand fracture. It is simple but has risk of ascending infection through the pin and bony injury by multiple drilling. Ascending infection through pin tract is mostly superficial and can be treated with antibiotics and aseptic dressing. This is a case review of subacute osteomyelitis on phalangeal bones after Kirschner wire fixation with literature review. Methods: A 40-years-old man with distal phalangeal fracture on right second finger is presented. He went to a local clinic and had percutaneous Kirschner wire fixation under local anesthesia. He was transferred to our hospital for ulcerative wound on DIP joint at 4 weeks after operation. Radiography showed osteolytic change around medulla of middle and distal phalanges, leading to diagnosis of a subacute osteomyelitis. We treated it with amputation at the level of shaft of middle phalanx. Results: The postoperative course was uneventful. We thought several possible reasons for osteomyelitis in our case. First, it could resulted from ascending infection through the wire. Second, it could be resulted from a bony burn by repeated drilling. And bony necrosis could be a consequence of arterial insufficiency caused by 2 pin insertion. Conclusion: We suggest that a precise pinning based on accurate anatomical understanding is required for a percutaneous Kirschner wire fixation. The frequency of drilling should be minimized. Careful observation and patient education for pin site care are essential.

• Tunnel and Underground Space
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• v.19 no.5
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• pp.407-420
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• 2009

In this study geostatistical technique using indicator kriging was performed to evaluate the optimal rock mass classification by integrating the various geophysical information such as borehole data and geophysical data. To get the optimal kriging result, it is necessary to devise the suitable technique to integrate the hard (borehole) and soft (geophysical) data effectively. Also, the model parameters of the variogram must be determined as a priori procedure. Iterative non-linear inversion method was implemented to determine the model parameters of theoretical variogram. To verify the algorithm, behaviour of object function and precision of convergence were investigated, revealing that gradient of the range is extremely small. This algorithm for the field data was applied to a mountainous area planned for a large-scale tunneling construction. As for a soft data, resistivity information from AMT survey is incorporated with RMR information from borehole data, a sort of hard data. Finally, RMR profiles were constructed and attempted to be interpreted at the tunnel elevation and the upper 1D level.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.8
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• pp.801-806
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• 2015

Journal bearings support rotors using fluid film between the rotor and the stator. Generally, journal bearings are used in large rotor systems such as turbines in a power plant, because even in high-speed and load conditions, journal bearing systems run in a stable condition. To enhance the reliability of journal-bearing systems, in this paper, we study health-diagnosis algorithms that are based on the supervised learning method. Specifically, this paper focused on defining the unit of features, while other previous papers have focused on defining various features of vibration signals. We evaluate the features of various lengths or units on the separable ability basis. From our results, we find that one cycle datum in the time-domain and 60 cycle datum in the frequency domain are the optimal datum units for real-time journal-bearing diagnosis systems.

• Journal of the Korean Society for Nondestructive Testing
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• v.15 no.1
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• pp.291-298
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• 1995

An ultrasonic testing uses the directivity of the ultrasonic wave which propagates in one direction. The directivity is expressed as the relationship between the propagate direction and its sound pressure. This paper studied the directivity of shear waves emitted from angle probes and scattered from surface defects by using visualization method. These experimental results were compared with the theory which was based on the continuous wave. The applicability of continuous wave theory was discussed in terms of the parameter $d/{\lambda}$; where d is transducer or defect size and ${\lambda}$ is the wavelength. In the case of angle probes, the experimental results show good agreement with theoretical directivity on the principal lobe. When defect size was smaller than the wavelengths, clear directivity in the reflected wave was observed. In the case of the same ratio of defect size to wavelength, the directivity of reflected waves from the defect show almost the same directivity in spite of frequency differences. When the $d/{\lambda}$ is greater than 1.5, measured directivities almost agreed with the theoretical one.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1253-1262
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• 2001

Experimental study is conducted to investigate the heat/mass transfer and flow characteristics for the flow over backward-facing step and cavities. A naphthalene sublimation method has been employed to measure the mass transfer coefficients on the duct wall and LDV system has been used to obtain mean velocity profiles and turbulence intensities. Reynolds number based on the step height and free stream velocity is 20,000 and St numbers of acoustic excitations given to separated flow are 0.2 to 0.4. The spectra of streamwise velocity fluctuation show a sharp peak forcing frequency for an acoustically excited flow. The results reveal that the vortex pairing and overall turbulence level are enhanced by the acoustic excitation and a significant decrease in the reattachment length and the increased turbulence intensity are observed with the excitation. A certain acoustic excitation increases considerably the heat/mass transfer coefficient at the reattachment point and in the recirculation region. For the cavities, heat/mass transfer is enhanced by the acoustic excitation due to the elevated turbulence intensity. For the 10H cavity, the flow pattern is significantly changed with the acoustic excitation. However, for the 5H cavity, the acoustic excitation has little effect on the flow pattern in the cavity.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.291-296
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• 2013

The purpose of this study was to determine food safety practices and procedures based on Hazard Analysis Critical Control Point (HACCP) system and to suggest more effective method of HACCP implementation in meat packaging industry in Korea. We used the non-compliance rate of each evaluation item to compare the weak points of prerequisite requirements and HACCP. The prerequisite items related to facility, equipment, and tools showed inadequate level of requirements or unsanitary conditions for proper HACCP operation. A lack of understanding of sanitation standard operation procedures was identified as a fundamental barrier to HACCP implementation. High rate of non-compliance in HACCP items compared to prerequisite requirements signify that small businesses have potential difficulties of applying HACCP due to lack of technical expertise, financial resources for prerequisite requirements, and available personnel to prepare and operate HACCP plan. Also we suggest to revise and minimize current critical control points (CCPs). Time-temperature control of cold-storage rooms for carcasses and final products could be performed by control points of prerequisite requirements. As the occurrence frequency getting lower, metal detector should be replaced by intensified training of sanitary handling and safety procedure. This will be more effective and preventive measures against physical contaminants including metal particles. In conclusion, control point of prerequisite requirement may replace CCP in the plant with simple processing line and no heating process such as meat packaging industry.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.4
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• pp.330-337
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• 2010

In this paper, 3-dimensional electromagnetic numerical analysis is performed about the eddy current(EC) array probe characteristic which is the next generation probe for accurate diagnosis of steam generator(SG) in nuclear power plants(NPPs). ASME(American Society of Mechanical Engineers) Standard and X-probe combo calibration standard tube are selected for acquisition of eddy current testing(ECT) signals and this result of compared with the real test signals for reasonability of result. Based on the analysis result of calibration standard tube, ECT signals that are about the defects of pitting, stress corrosion cracking(SCC), multiple SCC and wear is obtained. Material of specimen was Inconel 600 which is usually used for SG tubes in NPPs. The operation frequency of 300 kHz were used. The signal characteristics could be observed according to the various defects. The results in this paper can be helpful when the ECT signals from EC array probe are evaluated and analyzed.

• Korean Journal of Medicinal Crop Science
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• v.11 no.4
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• pp.289-297
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• 2003

Using Agrobacterium-me야ated transformation method the auxin-regulated cotton GST (Gh-5) constructs were used to transform Rehmannia glutinosa L. The PCR analysis was conducted to verify transgenicity. Based on the PCR analysis, there was verified that the 988 bp DNA band had showed in transgenic plant genomes in PCR anaJysis using Gh5-1 and Gh5-2 primers. The effects of cocultivation with Agrobacterium tumefaciens, regeneration and selection conditions on the transformation efficiency of Chinese foxglove (Rehmannia glutinosa L.) were investigated. Factors such as cocultivation period, use of acetosyringone, postcultivation in darkness, and different kanamycin concentrations for selection were assessed. In vitro regeneration, the number of leaves, shoot lengths and numbers on MS medium were superior to on B5 and WPM medium, and the shoot formation rate was highest level of 95% in cultured base part containing leaf stalk. Addition of acetosyringone at concentration of $200{\mu}M$ to cocultivation medium and 3-day of cocultivation improved transformation frequencies. Exposure of explants to darkness for 4 weeks on selection medium resulted in further increased the regeneration frequency of transgenic shoots. In PCR analysis, the amplified fragments of Gh5 gene were detected (988 bp), and GST-expressing transgenic R. glutinosa L. plants had approximately three-fold higher activity in leaf extracts compared with control plant.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.22-30
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• 2006

In this paper, a systematic design method on an IPMC(ionic polymer-metal composite)-driven ZNMF(zero-net-mass-flux) pump is introduced for the flow control of an MAV's (micro air vehicle) wing. Since the IPMC is able to generate a large deformation under a low input voltage along with its ability to operate in air, and is easier to be manufactured in a small size, it is considered to be an ideal material of the actuating diaphragm. Through the numerical methods, an optimal shape of the IPMC　diaphragm was found for maximizing the stroke volume. Based on the optimal IPMC diaphragm, a proto-type ZNMF pump with a slot, was designed. By using the flight speed of the MAV considered in this work, the driving frequencies(~ 40 Hz) of IPMC diaphragm, and the flow velocity through the pump's slot, the calculated non-dimensional frequency and the momentum coefficient ensure the feasibility of the designed ZNMF pump as a flow control device.