• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.39-52
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• 2000

A design of 2 stage S-DLVA(successive detector log video amplifier) was studied to detect wide dynamic radar pulse ranging from -70 ㏈m to 0㏈m. A basic design idea was focused on the linear detection in logarithmic scale of wide dynamic range radar pulses from nosie-like weak power of -70 ㏈m to relatively high power 0 ㏈m. It is highly formidable, since it requires high speed detection less than 10 nsec over the operating frequency ranges from 6 to 18 ㎓. A limiter diode, a tunnel diode and an L17-C were used as a protecting device, a detector diode and a log video amplifier in companion as a single stage detector to give voltage output proportional to the input power of about 35 ㏈ dynamic range. A protype of 2-stage DLVA having one more single stage detector was fabricated with a 32 ㏈ low noise amplifier and a 3 ㏈ hybrid coupler to provide total 70 ㏈ dynamic range detection. The logging characteristics were measured to have log slope of 25m.V/㏈ against 70 ㏈ logging range from -55 ㏈m to +15 ㏈m, the log linearity of within +/- 1.5 ㏈, and tangential sensitivity was at -63 ㏈m. The pulse dynamics of rise time and recovery time were measured as 50 nsec and 1.2 $\mu$sec, respectively. The reason might be due to the parasitic capacitances of packaged limiter, tunnel diode, and L17-C.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.225-230
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• 2010

The purpose of the study was to apply and to expand the six sigma to reduce waiting times for computed tomography (CT) examination which manipulated by the department of radiology. It was preceded by DMAIC (Define, Measure, Analyze, Improve, and Control). In the stage of definition, it wereselected for total 5 critical to quality (CTQ), which were the kindness, the waiting time, the examination explanation, the waiting day and the waiting stand environment, that increased the reserved time of CT examination. In the stage of measurement, the number of examinations and of reservation waiting days performed and resulted in final CTQ(Y) which measured each 1.68 and 1.85 sigma. In the stage of analysis, the examination concentrated on morning time, non-scheduled examination of the day, the delayed time of booking, frequent telephone contacting and equipment malfunction were determined as variable key causes. In the stage of improvement, it were performed with expansion of the examination in the morning time, integration of laboratories that used to in each steps, developing the ability of simultaneous booking schedule for the multiple examinations, developing program of examination request, and the customer management team operations. For the control, the number of examinations and reserved waiting days were measured each 3.14 and 1.13 sigma.

• Journal of Korea Water Resources Association
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• v.43 no.3
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• pp.265-273
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• 2010

This study proposed the method that can calculate discharge using hydraulic characteristics that can acquire easily-comparatively such as hydraulic radius, bed slope, depth to improve the stage-discharge curve equation considering only stage. Roughness coefficient n value and C value that hydraulic characteristics of rivers is reflected from Manning's equation and Chezy's equation using the measured data of the natural open channel in the report of Albert University estimated and calculated discharge on the basis of this. The method proposed in this study was calculated stunningly to measured discharge. And that compared with discharge by existent stage-discharge curve.

• Journal of Veterinary Clinics
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• v.38 no.5
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• pp.215-220
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• 2021

The purpose of this study was to investigate the correlation between vertebral left atrial size (VLAS) and NT-proBNP levels. Sixty-three dogs with myxomatous mitral valve disease (MMVD) were recruited for this study. The MMVD group was classified according to the ACVIM stage based on medical history, clinical signs, and thoracic radiography and echocardiography findings. The N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured using fluorescent immunoassay. VLAS and VHS values were measured using a digital caliper in the right lateral view. There were significant differences in VLAS for each American college of veterinary internal medicine (ACVIM) stage (p < 0.01). As the ACVIM stage increased, it tended to increase. Vertebral heart score (VHS) also showed a tendency to increase with the ACVIM stage (p < 0.01). VLAS was divided into three groups: VLAS <2.6, 2.6≤ VLAS <3.1, and VLAS ≥3.1. NT-proBNP values were significantly different between the three groups (p < 0.01), and VLAS and NT-proBNP values showed a strong positive correlation (r = 0.756, p < 0.01). In conclusion, there were significant differences among ACVIM stages B1 and B2, B1 and C-D, and B2 and C-D groups regarding VLAS. Furthermore, NT-proBNP increased proportionally as VLAS increased. Measurements of VLAS may be helpful in the diagnosis of MMVD in addition to the existing radiological and echocardiographic methods.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.425-438
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• 2015

This study proposes a three-stage model of R&BD performance which captures commercialization outcomes as well as conventional R&D performance. The model is composed of three factors : inputs (R&D budgets and researchers), outputs (patents and papers), and outcomes (technical fees, products sales, and cost savings). Three stages are defined for each transformation process between the three factors : efficiency stage from input to output (stage 1), effectiveness stage from output to outcome (stage 2), and productivity stage from input to outcome (stage 3). The performance of each stage is measured by data envelopment analysis (DEA). DEA is a non-parametric efficiency measurement technique that has widely been used in R&D performance measurement. We measure the performance of 171 projects of 6 public R&BD programs managed by Seoul Business Agency using the proposed three-stage model. In order to provide a balanced and holistic view of R&BD performance, the R&BD performance map is also constructed based on performance of efficiency and productivity stages.

• Progress in Superconductivity and Cryogenics
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• v.12 no.2
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• pp.29-33
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• 2010

The experimental results of the 2 stage Gifford-McMahon(GM) type pulse tube refrigerator (PTR) or cryopump are presented in this paper. The objectives of his study are to develop design technology of the integral type 2 stage PTR which rotary valve is directly connected to he hot end of the regenerator and acquire its improved performance. Design of the 2 stage PTR is conducted by FZKPTR(Forschungs Zentrum Karlsruhe Pulse Tube Refrigerator) program for the design of pulse tube refrigerators. The fabricated PTR has U-type configuration and incorporates orifice valve, double-inlet valve and reservoir as phase control mechanism. Rotary valve is used to make pulsating pressure and is directly connected to inlet of $1^{st}$ stage regenerator. From experiments, cooling performance map and pressure waveform at each point were measured for different operating frequencies. Experimental results show the best cooling performance with 2 Hz operation in spite of small pressure amplitude. The lowest temperatures of the 2 stage PTR were 16.9 K at the second stage and 58.0 K at the first stage. The cooling capacities achieved were 14.4 W at 79 K, the first stage and 3.6 W at 29 K, the second stage.

• The Journal of Advanced Prosthodontics
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• v.1 no.3
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• pp.124-128
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• 2009

STATEMENT OF PROBLEM. How the ISQ values measured by $Osstell^{TM}$ and $Osstell^{TM}$ Mentor are related, and whether the ISQ values acquired from the two machines changes in accordance with changes in implant stability are not yet fully understood. PURPOSE. The aim of this study was to find out correlation between the ISQ values acquired from $Osstell^{TM}$ and $Osstell^{TM}$ Mentor, and to evaluate the clinical effectiveness and accuracy of two devices. MATERIAL AND METHODS. Sixty two implants were inserted into 47 patients, and their ISQ values were measured using $Osstell^{TM}$ and $Osstell^{TM}$ Mentor. In the first stage surgery, the ISQ values of forty four implants inserted into thirty five patients were measured. In the second stage surgery, the values of fifty implants inserted into thirty seven patients were measured. The values were analyzed to determine the difference between the mean ISQ values of $Osstell^{TM}$ and $Osstell^{TM}$ Mentor. In addition, the correlation between implants used in the first and second stage of surgery with regard to their types and areas of insertion were analyzed. The difference between the ISQ values of 32 implants in each patient during the first and second stage was analyzed. The statistical assessment was carried out using SPSS V. 12.0 for Win. (SPSS Inc., Chicago, USA). The Pearson correlation coefficient was used to examine the correlation between $Osstell^{TM}$ and $Osstell^{TM}$ Mentor in the first and second stages of surgery, whereas the difference between their ISQ values was evaluated using a paired t-test. RESULTS. In the first stage, the mean ISQ value for $Osstell^{TM}$ and $Osstell^{TM}$ Mentor was 70.84 and 75.09, respectively, showing a significant difference (P < .01). In the second stage, the mean ISQ value of $Osstell^{TM}$ and $Osstell^{TM}$ Mentor was 71.76 and 75.94, respectively, also showing a significant difference (P < .01). The difference between the ISQ values in patients in the first and the second stages was significant with both instruments. CONCLUSION. The significant difference in the values obtained using the $Osstell^{TM}$ and $Osstell^{TM}$ Mentor between the first and second stages of implant surgery indicates that these values can be a convenient and precise way for evaluating the implant stability in clinical practice.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.1-9
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• 2009

This study is focused on the analysis of loop characteristics of stage-discharge relation which is widely used for the production of discharge data and the simulation of loop stage-discharge relation using the numerical model. Analysis of consecutive stage and discharge data at 3 points revealed that loop of stage-discharge relationship is very strong. This means that the existing single stage-discharge relation may include large amount of error. Various flood events are simulated in mainstream of Han river with one-dimensional numerical model. The calculated stage data are compared with measured data. Especially continuous field-flow measurements concurrently collected with an Acoustic Doppler Velocity Meter (ADVM) on Hangang bridge in the case of 2007 flood event are used to verify the model applicability of estimating flows in open channels. This comparison shows that numerical model is an accurate and reliable alternative for making the real stage-discharge relation. Simulation of stage-discharge relation by a numerical model at Paldang and Hangang bridge showed good agreements with measured one, so it may be possible to generate real loop stage-discharge relation with properly calibrated and verified numerical model. It can be concluded that results of this study can contribute to error analysis of conventional single stage-discharge relation and development of loop stage-discharge relation with numerical model.

• JSTS:Journal of Semiconductor Technology and Science
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• v.1 no.1
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• pp.84-93
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• 2001

An electromagnetic micro x-y stage for probe-based data storage (PDS) has been fabricated. The x-y stage consists of a silicon body inside which planar copper coils are embedded, a glass substrate bonded to the silicon body, and eight permanent magnets. The dimensions of flexures and copper coils were determined to yield $100{\;}\mu\textrm{m}$ in x and y directions under 50 mA of supplied current and to have 440 Hz of natural frequency. For the application to PDS devices, electromagnetic stage should have flat top surface for the prevention of its interference with multi-probe array, and have coils with low resistance for low power consumption. In order to satisfy these design criteria, conducting planar copper coils have been electroplated within silicon trenches which have high aspect ratio ($5{\;}\mu\textrm{m}$in width and $30{\;}\mu\textrm{m}$in depth). Silicon flexures with a height of $250{\;}\mu\textrm{m}$ were fabricated by using inductively coupled plasma reactive ion etching (ICP-RIE). The characteristics of a fabricated electromagnetic stage were measured by using laser doppler vibrometer (LDV) and dynamic signal analyzer (DSA). The DC gain was $0.16{\;}\mu\textrm{m}/mA$ and the maximum displacement was $42{\;}\mu\textrm{m}$ at a current of 180 mA. The measured natural frequency of the lowest mode was 325 Hz. Compared with the designed values, the lower natural frequency and DC gain of the fabricated device are due to the reverse-tapered ICP-RIE process and the incomplete assembly of the upper-sided permanent magnets for LDV measurements.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.2
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• pp.167-175
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• 1993

Lithium-Carbon Intercalation Compounds(Li-CICs) have been synthesized from various carbon ma-terials by use of the modified stainless steel two-bulbs methods. These compounds had various colours by structural character of starting materials. The synthesized Li-CICs were identified to stage formation process by X-ray diffraction data. At these results, well-oriented natural graphite and graphite fiber are formed lower stages(Stage 1, Stage 2), but poor-oriented carbon fiber and petroleum cokes are also formed higher stages(Stage 3, Stage 4, Stage 5). And when we compared with measured d value and calculated d value, these values agreed with each other. But poor-oriented carbon materials are some difference from them. The stage stability and energy stage of Li-CICs were obtained by UV/VIS Spectrophotometric data. X-ray diffraction and UV/VIS Spectrophotometric data suggested that well-oriented carbon materials has distingushible curve between energy and reflectance. In these results, we know that many charge carriers between carbon layers are related to concentration of intercalants. And then, this paper also provides information on high efficiency energy storing materials at intercalation process of Li-CICs.