• Journal of the Korean Vacuum Society
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• 제16권5호
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• pp.388-396
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• 2007

KSTAR (Korea Superconducting Tokamak Advanced Research) current lead system (CLS) has a role to interconnect magnet power supply (MPS) in room temperature (300 K) and superconducting (SC) bus-line, electrically. For the first plasma experiments, it should be assembled 4 current leads (CL) on toroidal field (TF) current lead box (CLB) and 14 leads on poloidal field (PF) CLB. Two current leads, with the design currents 17.5 kA, and SC bus-lines are connected in parallel to supply 35 kA DC currents on TF magnet. Whereas, it could supply $20\;{\sim}\;26\;kA$ to each pairs of PF magnets during more than 350 s. At the cold terminals of the leads, there are joined SC bus-lines and it was constructed helium coolant control system, aside from main tokamak system, to protect heat flux through current leads and enhanced Joule heat due to supplied currents. Throughout the establishment processes, it was tested the high vacuum pumping, helium leak of the helium lines and hardwares mounted between the helium lines, flow controls for CL, and liquid nitrogen cool-down of possible parts (current leads, CL helium lines, and thermal shield helium lines for CLB), for the accomplishment of the required performances.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.201-206
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• 2010

A project for construction of Korea Geodetic VLBI has officially started in Oct. 2008. The construction of all system will be completed by the end of 2011. The project was named Korea VLBI system for Geodesy (KVG), and its main purpose is to maintain the Korea Geodetic Datum. In case of the KVG system, an observation room where an H-maser frequency standard is located is in a building separated from an antenna by several tens of meters. Therefore KVG system will adopt a so-called round-trip system to transmit reference signals to the antenna with diminishing the effect of path length variations. KVG's round-trip system is designed not only available to use either metal or optical fiber cables, but also available to measure path length variations directly by using K5/VSSP32 sampler. We will present principle of round-trip system and the new type of round trip system for KVG.

• Structural Engineering and Mechanics
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• 제58권5호
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• pp.869-886
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• 2016

Non-Deformable Support System (NDSS) is one of the support system analysis methods. It is likely seen as numerical analysis. Obviously, numerical modeling is the key tool for this system but not unique. Although the name of the system makes you feel that there is no deformation on the support system, it is not true. The system contains some deformation but in certain tolerance determined by the numerical analyses. The important question is what is the deformation tolerance? Zero deformation in the excavation environment is not the case, actually. However, deformation occurred after supporting is important. This deformation amount will determine the performance of the applied support. NDSS is a stronghold analysis method applied in full to make this work. While doing this, NDSS uses the properties of rock mass and material, various rock mass failure criteria, various material models, different excavation geometries, like other methods. The thing that differ NDSS method from the others is that NDSS makes analysis using the time dependent deformation properties of rock mass and engineering judgement. During the evaluation process, NDSS gives the permission of questioning the field observations, measurements and timedependent support performance. These transactions are carried out with 3-dimensional numeric modeling analysis. The goal of NDSS is to design a support system which does not allow greater deformation of the support system than that calculated by numerical modeling. In this paper, NDSS applied to the problems of Tunnel 34 of the same Project (excavated with NATM method, has a length of 2218 meters), which is driven in graphite schist, was illustrated. Results of the system analysis and insitu measurements successfully coincide with each other.

• Progress in Superconductivity and Cryogenics
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• 제5권1호
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• pp.123-127
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• 2003

For disseminating a ney IEC international standard of critical trmperature of NbTi,Nb$_3$Sn and Bi-2223 Composite Suterconductors, we develpted a measuring system and studied standardization of test method. The measuring system consisted of cryogenic reservoir, base plate, thermometer, voltmeter and current source. Various specimens of the Nbti, Nb$_3$Sn and Bi-2223 composite superconductors were tested using this system for measuring their critical temperatures. After measuring the resistance-temperature relation, the data were compensated with thermoelectric voltages for NbTi Nb$_3$Sn specimens. NbTi specimens showed 9.2 K ~ 9.5 K of transition temperature and Nb$_3$Sn specimen showed about 18 K. Bi-2223 specimens showed 104 K ~ 107 K of transition temperature.

• Proceedings of the KIEE Conference
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.9-11
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• 1993

This paper decribed the development of Thermal Imaging Oservation System(TIOS) using the serial-parallel scan method. The detectors scan five lines at a time. These are put into serial order by electronic scan converter. Digital memory and high speed multiplexer are used for the serial conversion instead of charge coupled devices. As a result, thermal imaging system be presented with exellent performance which MRTD value is less than $0.5^{\circ}K$ at 7.5 cycles/mm.

• Proceedings of the KIEE Conference
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.543-545
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• 1993

This paper decribed the development of Thermal Imaging Oservation System(TIOS) using the serial-parallel scan method. The detectors scan five lines at a tine. These are put into serial order by electronic scan converter. Digital memory and high speed multiplexer are used for the serial conversion instead of charge coupled devices. As a result, thermal imaging system be presented with exellent performance which MRTD value is less than $0.5^{\circ}K$ at 7.5 cycles/mm.

• Journal of the Korean Society of Marine Environment & Safety
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• 제18권4호
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• pp.365-370
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• 2012

International Organization for Standardization has recently published ISO 12215-5 which is the small craft-hull construction and scantling. According to ISO 12215-5 AnnexB, the scantling determination can be accomplished by drop test for craft with a length $L_H$ of 2.5m up to 6m and single-skin construction. The current method, however, of visual test has the issue where it is difficult to make an objective evaluation of ship body strength. In this study, in order to develop an evaluation system that can make a quantitative evaluation of the drop test of leisure boats, the domestic/foreign regulations on drop test of leisure boats are analyzed and the drop test evaluation system is designed, and the system applicability is reviewed through 5-meter level aluminum ship, and the issues incurred by the state of the ship and the posture while dropping were checked.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제33권4호
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• pp.367-372
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• 2000

A series of experiment was conducted to investigate the relationship between ammoia removal rate and ammonia loading rates in seawater filtering system using rotating biological contactor (RBC). In this experiment, RBC system was consisted of rotating polyvinyl film disks, which provided $12 m^2$ of total effective surface area in $0.075 m^3$ of volume. $NH_4Cl$ was added by $10{\~}150 g$ as a ammonia nitrogen source to determine ammonia removal rate in RBC system. Relationship between time required for ammonia removal (y: hour) and nitrogen inputted ($x: NH_4-N mg/l$) in RBC system was as followed: $y=3.51+7.76 lnx (r^2=0.936)$. At ammonia concentration $2 mg/l$, it took 10 hour for removal of ammonia in the RBC system. However, at ammonia concentration of $5 and 16.5 mg/l$, it took 16 and 27 hours, respectively. There was a decreasing tencency of an increasing ammonia in the rearing water. Finally, the ammonia removal rate in the RBC system increased with the rise of total ammonia concentration up to $16.5 mg/l$.

• Journal of the Korea Society of Computer and Information
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• 제22권2호
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• pp.29-35
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• 2017

In this paper, we present a 5W1H programming model for IT non-experienced people who are not familiar with computer programming and those who need programming education. Based on this model, we can design a development tool that can be easily programmed by beginners. This development tool is a programming method applying the 5W1H concept and constructs a sentence to satisfy the control condition of 'Who, When, Where, What, and How', which is the sentence element of 5W1H. Therefore, the user can easily develop the target system as if constructing the sentence without learning the programming language of the target system. In this paper, to verify the effectiveness of the 5W1H programming model proposed in this paper, we applied the concept of 5W1H programming to Arduino and developed the development tool and performed the first verification and applied the second verification to the speech recognition smart home development platform.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권1호
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• pp.129-140
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• 2017

In this paper, a $4{\times}32$-channel neural recording system capable of acquiring neural signals is introduced. Four 32-channel neural recording ICs, complex programmable logic devices (CPLDs), a micro controller unit (MCU) with USB interface, and a PC are used. Each neural recording IC, implemented in $0.18{\mu}m$ CMOS technology, includes 32 channels of analog front-ends (AFEs), a 32-to-1 analog multiplexer, and an analog-to-digital converter (ADC). The mid-band gain of the AFE is adjustable in four steps, and have a tunable bandwidth. The AFE has a mid-band gain of 54.5 dB to 65.7 dB and a bandwidth of 35.3 Hz to 5.8 kHz. The high-pass cutoff frequency of the AFE varies from 18.6 Hz to 154.7 Hz. The input-referred noise (IRN) of the AFE is $10.2{\mu}V_{rms}$. A high-resolution, low-power ADC with a high conversion speed achieves a signal-to-noise and distortion ratio (SNDR) of 50.63 dB and a spurious-free dynamic range (SFDR) of 63.88 dB, at a sampling-rate of 2.5 MS/s. The effectiveness of our neural recording system is validated in in-vivo recording of the primary somatosensory cortex of a rat.