• Journal of Satellite, Information and Communications
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• v.9 no.3
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• pp.15-21
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• 2014

An electrostatic discharge (ESD) protection device, so called, N-type embedded silicon controlled rectifier (NESCR), was analyzed for high voltage operating I/O applications. A conventional NESCR standard device shows typical SCR-like characteristics with extremely low snapback holding voltage, which may cause latch-up problem during normal operation. However, our modified NESCR_CPS_PPW device with proper junction/channel engineering such as counter pocket source (CPS) and partial P-well structure demonstrates highly latch-up immune current-voltage characteristics with high snapback holding voltage and on-resistance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.3D
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• pp.205-212
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• 2012

The national highway traffic counts system consists of short duration counts and continuous counts. Unlike continuous counts, short duration counts are performed by collection of a few days period and thus, the magnitude of deviation of collected data from AADT varies depending upon when data collection takes place. Therefore, this study was done to find out the best months and days of data collection of each highway classification in order to enhance the accuracy of AADT estimation. Continuous counts, another type of the national traffic counts system, are performed by collection of 365-day period using a permanent traffic counter. Therefore, it is necessary to keep the number of days for which the counter malfunctions to a minimum in order to enhance the accuracy of data. However, from time to time the permanent traffic counter malfunctions due to various causes and thus, cannot collect data. Therefore, this study was done to find out whether the age of counter, the ratio of heavy vehicle volume to total traffic volume, etc. could be the direct causes of counter's malfunction based on the number of maintenance for a certain time period.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.335-342
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• 2003

In this study, the effects of oxide layer formed on the contact parts of TiN coated ball and steel disk in sliding are investigated. Also wear mechanism to from the oxide layer and the characteristics of the oxide layer formation are investigated. AISI 52100 steel ball is used for the substrate of coated ball specimens. Two types of coated ball specimens were prepared by depositing TiN coating with 1 and 4 ${\mu}{\textrm}{m}$ in coating thickness. AISI 1045 steel is used for the disk type counter-body. To investigate the effect of oxide layer on the contact parts of the two materials, the tests were performed both in air for forming oxide layer on the contact parts and in nitrogen environment to avoid oxidation. And to study the effects of surface roughness of counter-body, TiN coating thickness and contact load of sliding test on the characteristics of oxide layer formation on counter-body, various tests were carried out. From the results, the friction characteristics between the two materials was predominated by iron oxide layer that formed on wear track on counter-body and this layer caused the high friction. And the formation rate of the oxide layer on wear track increased as the real contact area between the two materials increased as the contact load increased, the TiN coating thickness decreased and the surface of counter-body smoothened.

• The Journal of the Korea Contents Association
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• v.6 no.3
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• pp.1-11
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• 2006

With the improvement of information telecommunication technology, the various service in broadband integrated services digital networks have a wide range of delay, delay jitter and cell loss probability requirements according to traffic specification. Therefore, the design of appropriate control schemes that can satisfy the cell loss, delay requirements with various traffic specification for B-ISDN is an extremely important challenging problem. In this paper, we propose a priority control scheme using a window counter and a cell counter per each type of class. In the proposed priority control scheme, for satisfying required service quality, we performed the priority control scheme using the delay/loss factors obtained by comparing window counter with cell counter. The performance of proposed control scheme is estimated by computer simulation. In the results of simulation, we verified that the proposed method satisfied per class requirements as the results showed that cell loss probability has a order of video, data, voice and delay time has a order of video, voice and data.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.109-116
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• 2001

In this study, the effects of oxide layer formed on the contact parts of TiN coated ball and steel disk in sliding are investigated. Also wear mechanism to form the oxide layer and the characteristics of the oxide layer formation are investigated. AIS152100 steel ball is used for the substrate of coated ball specimens. Two types of coated ball specimens were prepared by depositing TiN coating with 1 and 4um in coating thickness. AISI1045 steel is used for the disk type counter-body. To investigate the effect of oxide layer on the contact parts of the two materials, the tests were performed both in ambient for forming oxide layer on the contact parts and in nitride environment to avoid oxidation. And to study the effects of surface roughness of counter-body, TiN coating thickness and contact load of sliding test on the characteristics of oxide layer formation on counter-body, various tests were carried out. From the results, the friction characteristics between the two materials was predominated by iron oxide layer that formed on wear track on counter-body and this layer caused the high friction. And the formation rate of the oxide layer on wear track increased as the real contact area between the two materials increased as the contact load increased, the TiN coating thickness decreased and the surface of counter-body smoothened.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.205-212
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• 2000

Experimental investigations on the removal of protein, total suspended solids and turbidity from aquacultural water were carried out by using three types of foam separator: counter current air driven type foam separator (CCADFS), high speed aeration type foam separator (HSAFS) and venturi type foam separator (VFS). The decrease of flow rate by CCADFS, HSAFS and VFS were $0.4,\;66.1,\;77.2 {\%}$ respectively. Protein removal rates by three types foam separator were decreased with the increased hydraulic residence time (HRT). Bellw 0.32 minute and 0.21 minute of hydraulic residence times, protein removal rate of HSAFS and YES was higher than that of CCADFS, respectively. Protein removal rate of VFS was lower than that of HSAFS at any HRT. As increasing the HRT, protein removal efficiency of CCADFS was increased, but that of HSAFS and VES were decreased. The changes of removal rates and efficiencies of total suspended solid and turbidity were similar to proteins.

• Membrane Journal
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• v.4 no.3
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• pp.142-151
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• 1994

Counter-current type reverse osmosis spiral wound module was manufactured for the separation and concentration of salf solution. The ratio of permeate volumetric flow rate vs. brine volumetric flow rate was effective parameter between rejection and degree of cocentration. The reflection coefficient was correspondent to the relation between rejection and degree of cocentration by Spiegler-Kedem model. Counter-current reverse osmosis process had more osmotic pressure drop effect and more degree of concentration than general reverse osmosis process. As a result of computer calculation, the extension of module length than module diameter was more effective for the increase of degree of concentration.

• Journal of Photoscience
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• v.8 no.3_4
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• pp.113-117
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• 2001

Several styrylquinolium salts were synthesized to investigate their absorption and thermal properties, which had five different p-aminobenzene units and three different counter ions (iodide, perchlorate, and hexafluorophosphorate anion), respectively. Hydroxy, methoxy, and methyl group in the meta position to the amino group led to bathochromic shift, while Ν-ethyl-Ν-chloroethylamino unit instead of Ν,Ν-diethylamino unit resulted in hypsochromic shift. A dye having a methoxy group in the meta position to the amino group had the highest molar extinction coefficient ($\xi$), while a dye carrying chloro group in Ν-alkyl chains had the lowest $\xi$. The type of counter ions had no effect on spectral properties like the maximum absorption wavelength and $\xi$. All styryl dyes had exothermic peaks at decomposition in DSC curves. Among these styryl dyes, S2 series with perchlorate anions showed the strongest exothermic decomposition. From TGA spectra, S3 series with hexafluorophosphorate anions had the best thermal stability and the sharpest threshold at thermal decomposition.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.504-516
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• 2017

The Jordan Research and Training Reactor (JRTR) is the first research reactor in Jordan, the commissioning of which is ongoing. The reactor is a 5-MWth, open-pool type, light-water-moderated, and cooled reactor with a heavy water reflector system. The neutron measurement system (NMS) applied to the JRTR employs a wide-range fission chamber that can cover from source range to power range. A high-sensitivity boron trifluoride counter was added to obtain more accurate measurements of the neutron signals and to calibrate the log power signals; the NMS has a major role in the entire commissioning stage. However, few case studies exist concerning the application of the NMS to a research reactor. This study introduces the features of the NMS and the boron trifluoride counter in the JRTR and shares valuable experiences from lessons learned from the system installation to its early commissioning. In particular, the background noise relative to the signal-to-noise ratio and the NMS signal interlock are elaborated. The results of the count rates with the neutron source and the effects of the discriminator threshold are summarized.

• Journal of Astronomy and Space Sciences
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• v.37 no.4
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• pp.249-255
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• 2020

We develop the tissue-equivalent proportional counter (TEPC) type's space radiation dosimeter to measure in-situ aviation radiation. That was originally developed as a payload of small satellite in the low-earth orbit. This dosimeter is based on a TEPC. It is made of an A-150 tissue-equivalent plastic shell of an internal diameter of 6 cm and a thickness of 0.3 cm. TEPC is filled with pure propane at 13.9 torrs to simulate a cell diameter of 2 ㎛. And the associated portable and low power electronics are also implemented. The verification experiments have been performed by the calibration experiments at ground level and compared with Liulin observation at aircraft altitude during the flight between Incheon airport (ICN) and John F. Kennedy airport (JFK). We found that the TEPC dosimeter can be used as a monitor for space radiation dosimeter at aviation altitude based on the verification with Liulin observation.