• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.87-88
• /
• 2006

In this paper, we propose a new selective scanning scheme based on hand-off path information, which can provide an efficient reducing of delay time. This scheme eliminates almost of the scanning delay time by using Selective Scan based on Experience Path Table(SSEPT) algorithm and also completed hand-off within few milliseconds by using the next candidate channel indexing mechanism. Our scheme reduces the total number of scanning channels as well as the delay time on each channel. From the simulation result, we show that the proposed scheme is advantageous over the legacy schemes in terms of the scanning channels and the total delay time.

• Journal of radiological science and technology
• /
• v.32 no.4
• /
• pp.453-460
• /
• 2009

The purpose of this study was to determine the dose distribution and image quality according to slice thickness and BC(beam collimation) in the gantry aperture. CT scans were performed with a 64-slice MDCT(Brilliance 64, Philips, Cleveland, USA) scanner. To determine the dose distribution according to BC, a ionization chamber was placed at isocenter and 5, 10, 15, 20, 25 and 30 cm positions from the isocenter in the 12, 3, 6 and 9 o'clock directions. The dose distribution for phantom scan was also measured using CT head and body dose phantom with five holes at the center of the phantom and the positions of the 12, 3, 6 and 9 o'clock directions. The image noise measurement for different BCs was performed using an AAPM CT phantom. Water-filled block of the phantom was moved by 5 cm or 10 cm to the 12 o'clock direction, and the image noise was measured at the center of the phantom, and the points of 12, 3, 6 and 9 o'clock direction respectively. Some points were placed beyond the scan field of view (SFOV), so that measurement was not possible at that points. The results are as follows: The CTDIw showed a larger decrease as the source goes farther from the iso-center or the BC became wider. The CTDIw depends on the BC width more than the number of the channel of a detector array. The value of CTDIW decreased with increasing BC, but the value decreased 16.6~31.9% in the head phantom scan in air scan and 51.0~64.5% in the body phantom scan. The value of the noise was 3.9~5.9 in the head and 5.3~7.4 in the body except for BC of $2{\times}0.5\;mm$, regardless of the degree of deviation from the iso-center. When a subject was located within the SFOV, the position did not significantly affect image quality even if the subject was out of the center.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.211.1-211.1
• /
• 2012

The on-orbit test simulation for predicting the instrument directional responsivity was conducted by the Monte Carlo based integrated ray tracing (IRT) computation technique and analytic flux-to-signal conversion algorithms. For the on-orbit test simulation, the Sun model consists of the Lambertian scattering sphere and emitting spheroid rays, the Amon-Ra instrument is a two-channel including a broadband scanning radiometer (energy channel) and an imager with ${\pm}2^{\circ}$ FOV (visible channel). The solar radiation produced by the Sun model is directed to the instrument viewing port and traced through the dual channel optical train. The instrument model is rotated on its rotation axis and this gives a slow scan of the Sun model over the full field of view. The direction of the incident lights are fed with scanned images obtained from the visible channel instrument. The instrument responsivity was computed by the ratio of the incident radiation input to the instrument output. In the radiometric simulation, especially, measured BRDF of the 3D CPC was used for scattering effects on radiometry. With diamond turned 3D CPC inner surface, the anisotropic surface scattering model from the measured data was applied to ray tracing computation. The technical details of the on-orbit test simulation are presented together with field-of-view calibration plan.

• Journal of Biomedical Engineering Research
• /
• v.28 no.6
• /
• pp.803-810
• /
• 2007

Although synthetic aperture focusing techniques can improve the spatial resolution of ultrasound imaging, they have not been employed in a commercial product because they require a real-time N-channel beamformer with a tremendously increased hardware complexity for simultaneous beamforming along M multiple lines. In this paper, a hardware-efficient beamformer architecture for synthetic aperture focusing is presented. In contrast to the straightforward design using NM delay calculators, the proposed method utilizes only M delay calculators by sharing the same values among the focusing delays which should be calculated at the same time between the N channels for all imaging points along the M scan lines. In general, synthetic aperture beamforming requires M 2-port memories. In the proposed beamformer, the input data for each channel is first upsampled with a 4-fold interpolator and each polyphase component of the interpolator output is stored into a 2-port memory separately, requiring 4M 2-port memories for each channel. By properly limiting the area formed with the synthetic aperture focusing, the input memory buffer can be implemented with only 4 2-port memories and one short multi-port memory.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.10 no.1
• /
• pp.55-60
• /
• 2014

Today, there is increasing the elderly population in rural community, and people of returning from the urban to the rural community are demand to be of high value-added agriculture. In this time, there are required to regularization, standardization, automation, for getting of production of high value crops. In this paper, we are study for automation cultivation control system design for produce high-value crops. this system were designed of two parts that one part is measure and control unit, another part is server part for database and server side control. the main controller for measurement and control is used MC9S08AW60, server for Database and server-side control was using MySQL with CentOS. The source code of control program was coding C and compile with GCC. the functions of measurement and control unit are digital input and output each 8channels and can be scan-able of 20 Bit with 2CH/Sec. Analog Output were designed that can be output of 4-20mA or 0-5V on 4channel. The Digital input and output part were designed 8-channel, and using the high speed photo coupler and relays. We showed that system is possible to measure a 20bit data width, 2Ch/sec as 8 channel analog signals.

• Atmosphere
• /
• v.23 no.4
• /
• pp.453-470
• /
• 2013

As a part of the KIAPS Observation Processing System (KOPS), we have developed the modules of satellite radiance data pre-processing and quality control, which include observation operators to interpolate model state variables into radiances in observation space. AMSU-A (Advanced Microwave Sounding Unit-A) level-1d radiance data have been extracted using the BUFR (Binary Universal Form for the Representation of meteorological data) decoder and a first guess has been calculated with RTTOV (Radiative Transfer for TIROS Operational Vertical Sounder) version 10.2. For initial quality checks, the pixels contaminated by large amounts of cloud liquid water, heavy precipitation, and sea ice have been removed. Channels for assimilation, rejection, or monitoring have been respectively selected for different surface types since the errors from the skin temperature are caused by inaccurate surface emissivity. Correcting the bias caused by errors in the instruments and radiative transfer model is crucial in radiance data pre-processing. We have developed bias correction modules in two steps based on 30-day innovation statistics (observed radiance minus background; O-B). The scan bias correction has been calculated individually for each channel, satellite, and scan position. Then a multiple linear regression of the scan-bias-corrected innovations with several predictors has been employed to correct the airmass bias.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.12
• /
• pp.124-133
• /
• 2015

Electro interstitial scan shows potential as a non-invasive screening method. It can discriminate some diseases based on electric current response to induce low intensity direct current to limbs or local area of body. DDFAO was invented in France and it is claimed that multi-channel EIS(Electro Interstitial Scan) is useful for various diseases, especially, diagnoses of endocrine system such as diabetics are very effective. In this study, we verified the repeatability and sensitivity of DDFAO by using a RC phantom model and its clinical usefulness using data obtained from normal and diabetes subject groups. As a result, it showed the repeatability and the output change according to change of phantom characteristic, but it was hard to distinguish normal and patient groups non-invasively with just six surface electrodes of DDFAO. The repeatability and the clinical accuracy was not sufficient for screening or diagnostic purposes, as well. In spite of the results with low repeatability and accuracy conducted in this study, we still need further investigations to improve the EIS-based measurement method; EIS is very convenient and simple and it shows potential as a screening tool of the whole body health conditions rather than localized disease diagnosis.

• Journal of Digital Convergence
• /
• v.11 no.7
• /
• pp.237-242
• /
• 2013

When abdomen and pelvic were scanned with 128 channel MDCT, the gonadal exposure dose was measured with and without gonadal shield and the obtained images were evaluated. As a result, during abdominal MDCT scan, the gonadal exposure dose was measured $16.5{\pm}0.5$ mGy when the gonad shield was not used, and it was $7.5{\pm}0.3$ mGy when the large gonad shield($650m^2$) was used, which showed the effect of reduction in the gonadal exposure dose by 54%. During pelvic MDCT scan, the gonadal exposure dose was $9.5{\pm}0.3$ mGy when the gonad shield was not used, and it was $2.8{\pm}0.2$ mGy when the large gonard shield($650m^2$) was used, which showed the effect of reduction in the gonadal exposure dose by 70%. The images were obtained when using the gonad shield and when not using it during MDCT scan, and as a result of analyzing them with 5-point Likert scale, in the abdominal image, it was 4.1 points irrespective of whether using the gonad shield or not. And also, in pelvic scan, it was 1.2 points when the gonad shield was used, and 4.1 points when it was not used. With the results above, it is considered that during the abdominal 128-MDCT scan, by using the gonad shield, the images should be obtained without being degraded and the exposure dose must be reduced.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.4
• /
• pp.62-70
• /
• 2015

Recently the demand for projected capacitance touch screens is sharply growing especially for large screens for medical devices, PC monitors and TVs. Large touch screens in general need a controller of higher complexity. They usually have a larger number of driving and sensing lines, and hence it takes longer to scan one frame for touch detection leading to a low frame scan rate. In this paper, a novel touch screen control technique is presented, which scans each frame in two steps of simultaneous multi-channel driving. The first step is to drive all driving lines simultaneously and determine which sensing lines have any touch. The second step is to sequentially rescan only the touched sensing lines, and determine exact positions of the touches. This technique can substantially increase the frame scan rate. This technique has been implemented using an FPGA and an AFE board, and tested using a commercial 23-inch touch screen panel. Experimental results show that the proposed technique improves the frame scan rate by 8.4 times for the 23-inch touch screen panel over conventional methods.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.1
• /
• pp.135-139
• /
• 2015

We present a fine patterning method of conductive lines on polyimide (PI) and glass substrates using silver (Ag) nanoparticles based on laser scanning. Controlled laser irradiation can realize selective sintering of conductive ink without damaging the substrate. Thus, this technique easily creates fine patterns on heat-sensitive substrates such as flexible plastics. The selective laser sintering of Ag nanoparticles was managed by optimizing the conditions for the laser scan velocity (1.0-20 mm/s) and power (10-150 mW) in order to achieve a small gap size, high electrical conductivity, and fine roughness. The fabricated electrodes had a minimum channel length of $5{\mu}m$ and conductivity of $4.2{\times}10^5S/cm$ (bulk Ag has a conductivity of $6.3{\times}10^5S/cm$) on the PI substrate. This method was used to successfully fabricate an organic field effect transistor with a poly(3-hexylthiophene) channel.