• ETRI Journal
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• 제40권5호
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• pp.561-569
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• 2018

Modern communication systems employ wideband antennas with circular polarization (CP) radiation. In this work, asymmetric modified bow-tie (ABT) and symmetric modified bow-tie (SBT) slotted circularly polarized single-point probe-fed circular patch antennas with dimensions of $40mm{\times}40mm$ for wideband applications are proposed. A 10 dB RL bandwidth of 350 MHz with CP, 3 dB axial ratio (AR) bandwidth of 100 MHz, peak gain of 4.9 dBic, and 10 dB RL bandwidth of 530 MHz with CP, 3 dB AR bandwidth of 140 MHz, peak gain of 5 dBic are obtained for ABT and SBT slotted circular patch antennas, respectively. The proposed SBT slotted patch is scaled up and down to $50mm{\times}50mm$ and $30mm{\times}30mm$, respectively. The proposed scaled-up version offers 10 dB RL and 3 dB AR bandwidths of 340 MHz and 80 MHz, with a peak gain of 5 dBic. The scaled-down version offers 10 dB RL and 3 dB AR bandwidths of 710 MHz and 180 MHz, with a peak gain of 5.25 dBic. These prototypes are suitable to work in IEEE 802.11a WLAN, ISM, and IEEE 802.11ac applications. The measured and simulated results are then discussed and compared.

• 사상체질의학회지
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• 제18권2호
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• pp.68-82
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• 2006

1. Objectives and Methods The purpose of this study was to objectify the diagnosis of Sasang constitution. It was analyzed the adult men and women's [i] sound into 23 factors with PSSC-2004. The study was conducted by subjects inputting 2.5-3 sec of [i] of 586 adult men and women's voices to PSSC-2004. The statistical analysis are applied to three groups : total group, male group, female group. The group of total 586 was composed with 155 Soyangin, 230 Taeumin and 201 Soeumin. The male group was composed with 61 Soyangin, 127 Taeumin and 87 Soeumin. The female group was composed with 94 Soyangin, 103 Taeumin and 114 Soeumin. 2. Results (1) In total group, the Soyangin's code3 was significantly low compared with the others(P=0.011). In total group, the Taeumin's code2 and the Soyangin's code1 were significantly high compared with the others(p=0.007)(P=0.030). (2) In total group, the Soyangin's peak, 50 up in peak and under 3 in peak were significantly low compared with the others(P=0.003) (P=0.005)(P=0.023). (3) In total group, the Taeumin's rank7, rank8, rank9 and rank10 were significantly high compared with the others (P=0.013)(P=0.015) (P=0.016)(P=0.003). (4) In male group, the Soeumin's code3 was significantly high compared with the others(P=0.002). (5) In male group, the Soeumin's peak sum was significantly high compared with the others(P=0.009). It was significant for distinction between Soeumin and Soyangin at the result of post mortem. In male group, the Soeumin's 50 up in peak, 50 down in peak were significantly high compared with the others(P=0.049)(p=0.037). In male group, the Soeumin's under 3 in peak was significantly high compared with the others(P=0.016). It was significant for distinction between Soeumin and Soyangin at the result of post mortem. (6) In male group, the Soeumin's rank 2, rank 3 and rank 4 were significantly low compared with the others(P=0.011) (0.011)(0.024). (7) In female group, the Taeumin's code2 was significantly high compared with the others(P=0.023). In female group, the Soyangin's code1 was significantly low compared with the others (P=0.046). In female group, Soyangin's code-1 was significantly high compared with the others(P=0.024). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (8) In female group, the Taeumin's peak sum was significantly high compared with the others(P=0.024). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. In female group, the Taeumin's 50 up in peak was significantly high compared with the others(P=0.012). (9) In female group, the Taeumin's rank 7, rank 8, rank 9 and rank 10 were significantly high compared with the others (P=0.009) (P=0.013)(P=0.016)(P=0.023). 3. Conclusion From above result, there is the possibility of efficiency standardguide for constitutional diagnosis by analyzation of the voices.

• 한국안광학회지
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• 제4권1호
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• pp.63-68
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• 1999

공간주파수에 따른 contrast sensitivity를 측정할 수 있는 새로운 방법으로 차트를 제작하기 위해 차트 화면 최대 luminance값을 100%로 하여, 격자주파수의 mean luminance를 25, 50, 75%의 3개형태로 만들어 CS값 0 에서 $10^3$ 값이 되도록 하였다. 초등학생 5학년을 대상으로 공간주파수에 따른 CS값의 측정결과 평균 luminance 값이 떨어질수록 CS값은 감소되고, peak 위치도 low spatial frequency 쪽으로 이동하였다. 약시인 사람은 고주파수쪽에서 CS가 감소하거나, 전체주파수 공간에서 CS값이 감소하였다. 격자순응에 의해 CS 측정값은 순응된 공간주파수의 주변 영역에서 CS가 감소된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 2차
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• pp.147-151
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• 2010

In this study, the clay specimen of Busan-Gyeongnam region was used for unconfined compression test to compare the relationship formula between elasticity modulus at peak($E_f$), elasticity modulus at $q_u$/2($E_{50}$), and cohesion when the sample breaks down by region and by level of cohesion. As the result, the regional results were found to be in the range of $E_f$ = 14c~47c and $E_{50}$ = 43c~137c; by cohesion, the results for very soft ground was $E_f$ = 15c~40c and $E_{50}$ = 54c~101c, $E_f$ = 13c~63c and $E_{50$ = 40c~147c for soft ground, $E_f$ = 18c~47c and $E_{50}$ = 57c~144c for medium ground, and $E_f$ = 25c~45c and $E_{50}$ = 68c~115c for solid ground. The average of the relationship formula between elasticity modulus-cohesion for the clay used in this study was $E_f$ = 32c, $E_{50}$ = 93c. This is 2.5~5 times smaller than the existing relationship formula.

• 한국초전도ㆍ저온공학회논문지
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• 제5권1호
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• pp.111-117
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• 2003

In the design of the split type free displacer Stilting cryocooler the motion of the displacer is very important to decide the cooling capacity, which depends upon the working gas pressure, the swept volume in the compression space and the expansion space, operating frequency, the phase shift between piston and displacer, etc. In this study, Stirling cryocooler actuated by the electric farce of the dual linear motor is designed and manufactured. Cool down characteristics of the cold end with laser displacement sensor in the expander of the Stilting cryocooler is evaluated. The charging pressure was 15kg$_{f}$/$\textrm{cm}^2$ and operating frequency was 50Hz. Input power and the lowest temperature were about 32W and 67K, respectively. And, displacement of the piston is measured by LVDTs (Linear Variable Differential Transformers), displacement of thedisplacer is measured by laser optic method, and phase shift between piston and displacer is discussed. As the peak-to-peak pressure of the compressor was increased, peak-to-peak displacement of the displacer was increased. The peak-to-peak displacement of the displacer increases in the range of 0 - 64.5Hz(resonant frequency of the displacer), but decreases steeply when the operating frequency is bigger than the resonant frequency. Finally when the phase shift between displacements of the Piston and displacer is 45。, operating frequency is optimum and is decided by resonant frequency of the expander, mass and cross section area of the displacer and constant by friction and flow resistance.e.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.410.1-410.1
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• 2014

A soft-lithographic top-down approach is combined with an epitaxial layer transfer process to fabricate high quality III-V compound semiconductor nanowires (NWs) and integrate them on Si/SiO2 substrates, using MBE-grown ultrathin InAs as a source wafer. The channel width of the InAs nanowires is controlled by using solvent-assisted nanoscale embossing (SANE), descumming, and etching processes. By optimizing these processes, the NW width is scaled to less than 50 nm, and the InAs NWFETs has ${\sim}1,600cm^2/Vs$ peak electron mobility, which indicates no mobility degradation due to the size.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.860-868
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• 2018

This article presents a new design of earthquake instrumentation that is suitable for quick decision-making after the seismic event at the nuclear power plant (NPP). The main objective of this work is to ensure more availability of the NPP by expediting walk-down period when the seismic wave is incident. In general, the decision-making to restart the NPP after the seismic event requires more than 1 month if an earthquake exceeds operating basis earthquake level. It affects to the plant availability significantly. Unnecessary shutdown can be skipped through quick assessments of operating basis earthquake, safe shutdown earthquake events, and damage status to structure, system, and components. Multidecision parameters such as cumulative absolute velocity, peak ground acceleration, Modified Mercalli Intensity Scale, floor response spectrum, and cumulative fatigue are discussed. The implementation scope on the field-programmable gate array platform of this work is limited to cumulative absolute velocity, peak ground acceleration, and Modified Mercalli Intensity. It can ensure better availability of the plant through integrated decision-making process by automatic assessment of NPP structure, system, and components.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 3차
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• pp.55-60
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• 2010

Rockfill zones in CFRD consist typically of large granular materials, usually the maximum particle size up to several meters, which makes laboratory testing to determine the mechanical properties of rockfill difficult. Commonly, the design strength of the rockfills is obtained by scaling down the original rockfill materials and performing laboratory strength tests for the reduced size materials. The objective of the present study is to investigate the effect of particle size on the shear behavior and the strength for granular materials. A series of large-scale triaxial tests was conducted on large granular materials with the maximum particle size varying from 20 to 50mm. The test results showed that overall shear behaviors were similar between the samples with different particle sizes while there were slight differences in the magnitudes of the peak shear stress between the samples. In addition, a simulation of the granular material with the max. particle size of 20mm was performed using DEM code, $PFC^{2D}$, and compared with the test results. The deviatoric stress versus strain behaviors of experimental and numerical tests were found to be matched well up to the peak stress state.

• 사상체질의학회지
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• 제18권2호
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• pp.83-95
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• 2006

1. Objectives and Methods The purpose of this study was to objectify the diagnosis of Sasang constitution. It analyzed the adult male and female voices into 23factors using PSSC-2004. The study was conducted by subjects inputting 2.5-3 sec of [a] in 586 men and women's voices to PSSC-2004. The statistical analyses are applied to three groups: total group, male group, female group. The group with a total of 586 was composed of 155 Soyangin, 230 Taeumin and 201 Soeumin. The male group was composed with 61 Soyangin, 127 Taeumin and 87 Soeumin. The female group was composed with 94 Soyangin, 103 Taeumin and 114 Soeumin. Taeyangin were excluded for a more accurate statistical analysis. 2. Results (I) In total group, Taeumin's peak sum was significantly high compared with the others(P=0.021). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (2) In total group, the Soyangin's rank6, rank7 and rank8 were significantly high compared with the others (P=0.050)(0.043)(0.034). (3) In total group, the Soyangin's rank9 was significantly high compared with the others(P=0.025). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (4) In male group, the Soyangin's code3 was significantly high compared with the others(P=0.050). (5) In male group, the Soyangin's code1 was significantly low compared with the others(P=0.004). It was significant for distinction between Taeumin and Soyangin at the result of post mortem. (6) In male group, the Soyangin's rank1, rank2, rank3 and rank4 were significantly high compared with the others(P=0.017)(0.008) (0.005)(0.002). They were significant for distinction between Taeumin and Soyangin at the result of post mortem. (7) In female group, the Taeumin's code1 was significantly low compared with the others(P=0.016). It was significant for distinction between Taeumin and Soeumin at the result of post mortem. 3. Conclusion From above result, there is the possibility of efficiency standard gide for constitutional diagnosis by analyzation of the voices.

• 약학회지
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• 제29권3호
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• pp.144-151
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• 1985

Cathodic stripping voltammetric determination of traces of selenium in plant samples was studied. Stripping peak of selenium (IV) from Cu-Se intermettalic deposit in acidic media containing copper (II) ion is specific, highly sensitive and well defined, is successfully used for the quantitative determination of selenuin down to the level of 1ng/ml. Sample is burnt in a calorimeter bomb under the oxygen pressure of 40atm. and the selenium is absorbed in 0.1M NaOH. After the solution is filtrated, concentrated and acidified with HCl, then passed through a column of cation exchange resin in the $H^{+}$ form(Dowex 50X-8). The column eluate is analyzed for selenium by differential pulse cathodic stripping voltammetric method. Analytical results of selenium for NBS SMR is well agreement with the certified values. Results are given for a series of plant materials.