• Nuclear Engineering and Technology
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• 제56권1호
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• pp.70-77
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• 2024

A low energy ion irradiation system based on the deuterium arc ion source with a high perveance of 1 µP for a single extraction aperture has been successfully developed for the investigation of ion irradiation on plasma-facing components including the first mirror of plasma optical diagnostics system. Under the optimum operating condition for mirror testing, the ion source has a beam energy of 200 eV and a current density of 3.7 mA/cm². The ion source comprises a magnetic cusp-type plasma source, an extraction system, a target system with a Faraday cup, and a power supply control system to ensure stable long time operation. Operation parameters of plasma source such as pressure, filament current, and arc power with D₂ discharge gas were optimized for beam extraction by measuring plasma parameters with a Langmuir probe. The diode electrode extraction system was designed by IGUN simulation to optimize for 1 µP perveance. It was successfully demonstrated that the ion beam current of ~4 mA can be extracted through the 10 mm aperture from the developed ion source. The target system with the Faraday cup is also developed to measure the beam current. With the assistance of the power control system, ion beams are extracted while maintaining a consistent arc power for more than 10 min of continuous operation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.810-831
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• 2019

Recently, continuous dimensional emotion recognition from audiovisual clues has attracted increasing attention in both theory and in practice. The large amount of data involved in the recognition processing decreases the efficiency of most bimodal information fusion algorithms. A novel algorithm, namely the incomplete Cholesky decomposition based kernel cross factor analysis (ICDKCFA), is presented and employed for continuous dimensional audiovisual emotion recognition, in this paper. After the ICDKCFA feature transformation, two basic fusion strategies, namely feature-level fusion and decision-level fusion, are explored to combine the transformed visual and audio features for emotion recognition. Finally, extensive experiments are conducted to evaluate the ICDKCFA approach on the AVEC 2016 Multimodal Affect Recognition Sub-Challenge dataset. The experimental results show that the ICDKCFA method has a higher speed than the original kernel cross factor analysis with the comparable performance. Moreover, the ICDKCFA method achieves a better performance than other common information fusion methods, such as the Canonical correlation analysis, kernel canonical correlation analysis and cross-modal factor analysis based fusion methods.

• 대한기계학회논문집 C: 기술과 교육
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• 제5권1호
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• pp.23-52
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• 2017

바이오융합 및 의료기기 산업은 의학과 전기, 전자, 기계, 재료 등 공학이 융합되는 다학제간 응용기술 산업분야이다. 바이오 융합 및 의료기기를 이용해 인간의 삶의 질 향상을 목표로 하고 있으며 제품에 대한 인지도와 브랜드 파워가 매우 중요한 산업이다. 그러나, 자본/기술 의존형 산업으로 제품의 개발부터 생산까지 소요되어지는 기간이 길고 개별 제품의 시장 규모가 작고 수명주기가 짧다고 할 수 있다. 따라서 연구개발에 대한 지속적인 투자가 요구되어지는 산업으로 국가적인 차원에서 바이오벤처 기업들을 위해 기술적 지원, 제도적 뒷받침, 인력 양성 등의 산업생태계 전반을 활성화하고자 하는 노력이 필요하다.

• 한국분말재료학회지
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• 제27권6호
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• pp.509-519
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• 2020

A well-established characterization method is required in powder bed fusion (PBF) metal additive manufacturing, where metal powder is used. The characterization methods from the traditional powder metallurgy process are still being used. However, it is necessary to develop advanced methods of property evaluation with the advances in additive manufacturing technology. In this article, the characterization methods of powders for metal PBF are reviewed, and the recent research trends are introduced. Standardization status and specifications for metal powder for the PBF process which published by the ISO, ASTM, and MPIF are also covered. The establishment of powder characterization methods are expected to contribute to the metal powder industry and the advancement of additive manufacturing technology through the creation of related databases.

• Parasites, Hosts and Diseases
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• 제57권1호
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• pp.61-67
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• 2019

Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELISA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.

• ETRI Journal
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• 제37권6호
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• pp.1199-1210
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• 2015

Automatic emotion recognition based on facial cues, such as facial action units (AUs), has received huge attention in the last decade due to its wide variety of applications. Current computer-based automated two-phase facial emotion recognition procedures first detect AUs from input images and then infer target emotions from the detected AUs. However, more robust AU detection and AU-to-emotion mapping methods are required to deal with the error accumulation problem inherent in the multiphase scheme. Motivated by our key observation that a single AU detector does not perform equally well for all AUs, we propose a novel two-phase facial emotion recognition framework, where the presence of AUs is detected by group decisions of multiple AU detectors and a target emotion is inferred from the combined AU detection decisions. Our emotion recognition framework consists of three major components - multiple AU detection, AU detection fusion, and AU-to-emotion mapping. The experimental results on two real-world face databases demonstrate an improved performance over the previous two-phase method using a single AU detector in terms of both AU detection accuracy and correct emotion recognition rate.

• BMB Reports
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• 제44권5호
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• pp.352-357
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• 2011

The effect of human MutY homolog (hMYH) on the activation of checkpoint proteins in response to hydroxyurea (HU) and ultraviolet (UV) treatment was investigated in hMYH-disrupted HEK293 cells. hMYH-disrupted cells decreased the phosphorylation of Chk1 upon HU or UV treatment and increased the phosphorylation of Cdk2 and the amount of Cdc25A, but not Cdc25C. In siMYH-transfected cells, the increased rate of phosphorylated Chk1 upon HU or UV treatment was lower than that in siGFP-transfected cells, meaning that hMYH was involved in the activation mechanism of Chk1 upon DNA damage. The phosphorylation of ataxia telangiectasia and Rad3-related protein (ATR) upon HU or UV treatment was decreased in hMYH-disrupted HEK293 and HaCaT cells. Co-immunoprecipitation experiments showed that hMYH was immunoprecipitated by anti-ATR. These results suggest that hMYH may interact with ATR and function as a mediator of Chk1 phosphorylation in response to DNA damage.

• 폴리머
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• 제31권6호
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• pp.505-511
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• 2007

조직의 재생을 위한 지지체재료의 개발은 조직공학 분야의 연구에 있어서 매우 중요한 요인이다. 히알루론산은 조직을 수복하기 위한 체내이식용 구조물로써 널리 사용되고 있는 천연고분자이며, 이를 이용하여 본 연구에서는 히알루론산을 함유한 락타이드-글리콜라이드 공중합체(PLGA) 다공성 지지체를 유화동결 건조법으로 제조하였다. HA-PLGA 지지체는 수은다공도계, 전자현미경 및 물흡수성을 측정하여 특성을 결정하였다. 제조된 HA-PLGA 지지체의 다공도는 약 96.5%, 전체다공면적은 $261\;m^2/g$ 이였으며, 세포가 성장하기에 적합한 환경인 다공사이의 상호 연결이 전자주사현미경을 통해 관찰되었다. 또한 세포의 생존율과 성장률은 MTT(3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium-bromide) 방법을 이용하여 분석하였고, 사이토카인 및 수용성 약물의 방출경향을 확인하기 위하여 과립구-대식세포 집락자극인자(GM-CSF)를 지지체에 담지시킨 후 효소결합 면혁 흡착검사(ELISA)를 이용하여 이들의 방출경향을 확인하였다. 천연/합성 하이브리드 담체로서의 HA/PLGA 담체가 PLGA 단독으로 사용하였을 때와 비교하여 볼 때 세포의 증식이 우수하였고, 이는 히알루론산의 우수한 생체적합성 및 수분 보유능력에 기인된 것으로 사료된다.

• 폴리머
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• 제32권1호
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• pp.49-55
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• 2008

슈반세포는 강력한 말초신경 재생 효과를 가지고 있다. 그리고 신경 유도관으로 사용된 소장점막하조직(small intestinal submucosa, SIS)은 세포활성을 촉진하는 여러 가지 성장인자를 다량 함유하고 있고 이종이식의 면역 거부반응이 없는 생체물질로서 널리 사용되고 있다. 슈반세포는 Fischer 쥐의 좌골신경으로부터 분리하였고, 순수 배양된 슈반세포를 $2{\times}10^6$ 세포로 계산하여 SIS 스폰지에 파종하였다. 그리고 Fischer 쥐의 좌골신경 5 mm를 제거하여 신경과 제조된 스폰지를 연결하는 신경 외막 봉합을 실시하였다. 그런 후 1, 2주 및 4주 후 재생된 신경을 적출 한 후, H &E 염색과 S-100, GFAP 및 NF 면역조직화학염색을 실시하였다. 그 결과, SIS 스폰지와 슈반세포를 함께 이식한 군(Group II)은 아무것도 이식하지 않은 군(Control II)과 SIS 스폰지만 이식한 군(Group I) 보다 뚜렷한 양성반응을 보였고 손상을 받지 않은 군(Control I)과 별차이가 없는 양상을 보여주었다. 이는 SIS 스폰지와 슈반세포를 함께 이식했을 때 손상된 조직공학적 말초 신경 재생에 중요한 역할을 한 것으로 사료된다.

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.178-183
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• 2012

The design of the integrated quench protection (QP) system for the high current superconducting magnet (SCM) has been fabricated and tested for the toroidal field (TF) coil system of the Korea Superconducting Tokamak Advanced Research (KSTAR) device. The QP system is capable of protecting the TF SCM, which consists of 16 identical coils serially connected with a stored energy of 495 MJ at the design operation level at 35.2 kA per turn. Given that the power supply for the TF coils can only ramp up and maintain the coil current, the design of the QP system includes two features. The first is a basic fast discharge function to protect the TF SCM by a dump resistor circuit with a 7 s time constant in case of coil quench event. The second is a slow discharge function with a time constant of 360 s for a daily TF discharge or for a stop demand from the tokamak control system. The QP system has been successfully tested up to 40 kA with a short circuit and up to 34 kA with TF SCM in the second campaign of KSTAR. This paper describes the characteristics of the TF QP systems and test results of the plasma experiment of KSTAR in 2009.