• Current Optics and Photonics
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• 제6권6호
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• pp.608-618
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• 2022

By analyzing the signal-to-noise ratio (SNR) theory of the conventional true color night vision system, we found that the output image SNR is limited by the wavelength range of the system response λ₁ and λ₂. Therefore, we built a double-channel four-band true color night vision system to expand the system response to improve the output image SNR. In the meantime, we proposed an image fusion method based on principal component analysis (PCA) and nonsubsampled shearlet transform (NSST) to obtain the true color night vision images. Through experiments, a method based on edge extraction of the targets and spatial dimension decorrelation was proposed to calculate the SNR of the obtained images and we calculated the correlation coefficient (CC) between the edge graphs of obtained and reference images. The results showed that the SNR of the images of four scenes obtained by our system were 125.0%, 145.8%, 86.0% and 51.8% higher, respectively, than that of the conventional tri-band system and CC was also higher, which demonstrated that our system can get true color images with better quality.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.22-22
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• 2001

To produce reconstituted rabbit embryos with fetal fibroblasts, the present study was evaluated the efficiencies of the different fusion and activation conditions as assessments of subsequent development and chromosome in the embryos. New Zealand White rabbits were used throughout the study. Fetal fibroblasts collected from 22-d of fetuses were cultured in DMEM ＋ 10% FBS in 5% $CO_2$ in air. The culture was maintained for 10 passages. In every passage half of cell suspension were kept In frozen. From rabbits treated with FSH in 30% PVP solution and hCG, oocytes were surgically collected from oviducts at 14 h post-hCG injection and stripped off their cumulus cells by re-pipetting in a 300 IU hyaluronidase solution. Oocytes with an extruded first polar body and dense cytoplasm were enucleated by micromanipulation in Ham's F-10 medium＋7.5 g/$m\ell$ cytochalasin B. Euncleation was confirmed under a fluorescence microscope after staining with 5 g/$m\ell$ bisbenzimide for 2 min. Each enucleated oocyte was injected with a fetal fibroblast into a perivitelline space. Reconstructed eggs were compared fusion rates either at 2.0 ㎸/cm or 1.6 ㎸/cm(60 sec, double pulses). After fusion, all eggs were activated with the combination of 5 M ionomycin (5 min) and 10 g/$m\ell$ cycloheximide (CHX, 3h), and cultured in CRlaa medium and transferred into TCM199＋10% FBS on day 3. Although there was not significantly differ in fusion rate between treatments (60%, 2.0 ㎸/cm vs. 79.4%, 1.6 ㎸/cm), none of them in the eggs fused with 2.0 ㎸/cm developed to blastocyst. In comparison of development and chromosome status between different activation treatments (Group 1; 5 M ionomycin/10 g/$m\ell$ CHX, Group 2; 5 M ionomycin/5 g/$m\ell$ CHX ＋ 2 mM DMAP after fusion with 1.6 ㎸/cm), there were not differ in cleavage and development rates (67.3% and 28.9% in Group 1; 67% and 33% in Group 2). All out of 8 embryos evaluated in Group 1 appeared a normal diploid chromosome sets and mean number of cells (Mean SEM) on day 4.5 of culture was 141.5 23.15 (n=8). It can be concluded that the use of cycloheximide has not happened in chromosome abnormalities, and fetal fibroblasts can be used for cloning in rabbit.

• 대한의용생체공학회:의공학회지
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• 제25권1호
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• pp.71-76
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• 2004

척추 측만증 교정 시 유합 범위에 따른 수술 후 의 효과를 분석하기 위하여 King-Moe type II 형태의 척추 측만증 환자를 대상으로 이에 대한 수학적 유한 요소 모델을 개발하였다. 유한 요소 모델을 이용하여 척추경 나사못을 이용한 고정 및 강봉 감염술 형태의 수술모사를 수행하였으며, 유합 범위를 각기 달리하여 수술 시뮬레이션 후의 척추계의 변화 즉 Cobb 각도, 첨추체 축회전, 흉추 후만각 그리고 늑골고의 변화를 정량적으로 계산하였다. 해석 결과 강봉 감염술의 경우에서 보다 강봉을 척추경 나사못에 연결시키는 과정에서 훨씬 더 많은 Cobb각도의 변화를 얻을 수 있었다. 강봉 감염술 과정에서는 약간의 Cobb각도 감소를 유발시킬 수 있었으나 오히려 척추체 축회전과 늑골 돌출고의 증가를 나타내었다 아울러 강봉과 척추경 나사못의 체결 과정이 척추 후만각 유지에도 큰 역할을 하고 있음을 알 수 있었다. 유합 범위를 변곡 발생 추체의 위치 보다 한 단계씩 길게(T4-12) 하여 60o의 강봉 감염술을 시행하였을 경우 Cobb 각도를 두 배 감소시킬 수 있었으나 급격한 늑골고와 첨추체 축회전량의 증가가 유발되었다. 해석 결과 유합 범위는 만곡 흠추체에서 변곡이 발생되는 위치 보다 한 레벨씩 작게 선정하는 것이 최적의 유합 범위임을 알 수 있었다.

• Journal of Welding and Joining
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• 제29권1호
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• pp.85-89
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• 2011

Waste water is disposed to sewage disposal plant by underground PE double wall pipes. Various processes have been introduced to join PE pipes, but most of these methods have many disadvantages such as costs, lack of reliability and difficulties in joining, etc. Recently butt welding has been paid much attention to joint PE pipes as this process has many advantages such as cost, safety and reliability. In this study, newly developed heat plate, a patent-pending heat plate with a groove, was used to butt-weld PE double wall pipes with different misalignment gaps to simulate real underground conditions, and the butt welding temperature of PE pipe was determined by thermal analysis (Thermal Gravimetric Analysis, Differential Scanning Calorimetry and Dynamic Mechanical Analysis). The resulting joining characteristics of double wall pipes were compared with those from a conventional heat plate, in terms of stiffness, flattening and leakage tests. The results from the stiffness and flattening test showed that there were no big differences between the butt-welded joints made from these two plates. From the leakage test, although PE pipes welded with a conventional heat plate did leak below the required test conditions (10 min. at 0.75kgf/cm2), the pipes welded with a patent-pending grooved heat plate did not show any leakage even at a pressure 1.5 times higher than the required conditions. It was noted that by utilizing a grooved heat plate more complete fusion at the pipe joints could be obtained, which in turn induced a high quality joints.

• Journal of information and communication convergence engineering
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• 제14권1호
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• pp.1-8
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• 2016

Spectrum sensing in cognitive radio networks allows secondary users to sense the unused spectrum without causing interference to primary users. Cognitive radio requires more accurate sensing results from unused portions of the spectrum. Accurate spectrum sensing techniques can reduce the probability of false alarms and misdetection. In this paper, a two-stage spectrum sensing scheme is proposed for cooperative spectrum sensing in cognitive radio networks. In the first stage, spectrum sensing is executed for each secondary user using energy detection based on double adaptive thresholds to determine the spectrum condition. If the energy value lies between two thresholds, a fuzzy logic scheme is applied to determine the channel conditions more accurately. In the second stage, a fusion center combines the results of each secondary user and uses a fuzzy logic scheme for combining all decisions. The simulation results show that the proposed scheme provides increased sensing accuracy by about 20% in some cases.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.48-49
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• 2001

Cryogenic technology is one of the key technologies for fusion reactor equipped with superconducting coil for plasma confinement. The KSTAR(Korea Superconducting Tokamak Advanced Research)Project is in progress since 1996. Major parameters of the KSTAR tokamak are : major radius 1.8m, minor radius 0.5m, toroidal field 3.5 Tesla and plasma current 2MA with a strongly shaped plasma cross-section and double -null diverter. Considering practical engineering constraints, the KSTAR device is designed for a pulse length of 300 sec in up-graded operation mode but in the initial configuration would provide a pulse length of 20 sec provided by the poloidal coil system in base-line operation mode. The cryogenic system is composed as follows : cold box, helium compressor system, distribution box, helium gas buffer tank, helium gas purifying system, gas recovery system, liquid helium storage dewar, current lead box, current bus line and liquid nitrogen storage tank.

• 대한족부족관절학회지
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• 제15권3호
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• pp.115-118
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• 2011

족관절 내 히알루론산 주사 후 효과에 대한 참고 자료를 살펴 본 결과 대부분의 연구들이 족관절 내 히알루론산 주사에 대한 효과와 안전에 대해 긍정적으로 보고하고 있지만, 아직까지는 결론을 짓기는 어렵다고 하겠다. 추후 많은 환자를 대상으로 한 무작위 이중맹검 위약대조군 연구(randomized double-blind placebo-controlled trials)를 통해 그 결과를 평가해야 할 것으로 사료되며, 또한 장기 추시를 통해 효과 발현 시기 및 지속 기간을 평가해야 할 것이다.

• International Journal of Advanced Culture Technology
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• 제4권4호
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• pp.1-5
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• 2016

In this paper, we present the study on the proposed design of a real-time transmission of a video from the drone to broadcasting station (OBVan) by using F8L10D-N LoRa Module. Nowadays, LoRa technology is proved to be the mass of low cost, long range machine-to-machine connectivity. Particularly in the field of broadcasting and communication system, F8L10D-N LoRa RF Module spread spectrum technology with long transmission distance and strong penetrative ability that is double stronger than traditional FSK as well as PSK modulation scheme.

• Journal of Microbiology
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• 제34권3호
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• pp.248-254
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• 1996

$cdc103^+$ gene in Schizosaccharomyces pombe which is similar to the CDC3 gene in Saccharomyces cerevisiae was cloned and sequenced. Comparison of the predicted amino acid sequences of $cdc103^+$ and CDC3 revealed that they share significant similarity (43% identity and 56% identity or similarity) to each other. The gene product of CDC3 in S. cerevisiae is known to be a highly ordered ring of filaments that lies just inside the cytoplasmic membrane in the region of the mother-bud neck. In order to characterize the gene product of $cdc103^+$ in Schizosaccharomyces pombe, fusion proteins were used to generate the polyclonal antibodies specific for the gene product (cdc103p). In immunofluorescence experiments, these antibodies decorate the region of the septum formation as a double ring structure late in the cell division cycle.

• Carbon letters
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• 제15권1호
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• pp.71-76
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• 2014

Activated carbon nanofibers (ACNF) were prepared from polyacrylonitrile (PAN)-based nanofibers using $CO_2$ activation methods with varying activation process times. The surface and structural characteristics of the ACNF were observed by scanning electron microscopy and X-ray diffraction, respectively. $N_2$ adsorption isotherm characteristics at 77 K were confirmed by Brunauer-Emmett-Teller and Dubinin-Radushkevich equations. As experimental results, many holes or cavernous structures were found on the fiber surfaces after the $CO_2$ activation as confirmed by scanning electron microscopy analysis. Specific surface areas and pore volumes of the prepared ACNFs were enhanced within a range of 10 to 30 min of activation times. Performance of the porous PAN-based nanofibers as an electrode for electrical double layer capacitors was evaluated in terms of the activation conditions.