• Membrane and Water Treatment
• /
• 제9권4호
• /
• pp.211-220
• /
• 2018

Incorporating nano-materials in thin-film composite (TFC) membranes has been considered to be an approach to achieve higher membrane performance in various water treatment processes. This study investigated the rejection efficiency of three target compounds, i.e., reserpine, norfloxacin and tetracycline hydrochloride, by TFC membranes with different graphene oxide proportions. Graphene oxide (GO) was incorporated into the polyamide active layer of a TFC membrane via an interfacial polymerization (IP) reaction. The TFC membranes were characterized with FTIR, FE-SEM, AFM; in addition, the water contact angle measurements as well as the permeation and separation performance were evaluated. The prepared GO-TFC membranes exhibited a much higher flux ($3.11{\pm}0.04L/m2{\cdot}h{\cdot}bar$) than the pristine TFC membranes ($2.12{\pm}0.05L/m2{\cdot}h{\cdot}bar$) without sacrificing their foulant rejection abilities. At the same time, the GO-modified membrane appeared to be less sensitive to pH changes than the pure TFC membrane. A significant improvement in the anti-fouling property of the membrane was observed, which was ascribed to the favorable change in the membrane's hydrophilicity, surface morphology and surface charge through the addition of an appropriate amount of GO. This study predominantly improved the understanding of the different PA/GO membranes and outlined improved industrial applications of such membranes in the future.

• 산업기술연구
• /
• 제31권A호
• /
• pp.39-43
• /
• 2011

Coherent interferences can be rejected using the weighted spatial smoothing (WSS) technique that allows us to be able to completely decorrrelate coherent signals with their arrival angles known. Its effective array aperture, however, can be greatly decreased, in particular when there exist many interferences, thereby degrading the rejection capability. In this paper, we propose an improved spatial smoothing (IWSS) which, with an increased effective array aperture, provides better performance than the existing WSS. Moreover, the proposed beamformer employs multiple constraints so that the coherent interferences are completely cancelled. Simulation shows the superiority of the IWSS in comparison with the conventional WSS.

• 한국중재학회지:중재연구
• /
• 제21권3호
• /
• pp.115-136
• /
• 2011

In the past, Chinese arbitral system and Chinese arbitral associations were avoided by international society due to the cases which Chinese court rejected the recognition and enforcement of foreign arbitral awards based on rural protection. Especially Chinese court adjudicated to reject the recognition and enforcement of arbitral awards by interpreting public policy broadly. The abuse of public policy by court threats the existence of commercial arbitration system. Under this awareness, the author figured out Chinese court shows what kind of attitude about public policy of Chinese court in the present through analyzing the cases about rejection of enforcement in Chinese arbitral awards in order to analyze whether Chinese court still maintain the negative attitude like past or there exist changes with public policy which is one of the rejection reasons of recognition and enforcement in foreign arbitral awards as the central figure. Chinese court behaved in an uncooperative attitude about arbitral awards like that it reached a verdict to reject the enforcement of arbitral awards by reason of violation in public policy about several foreign arbitral awards at the beginning stage of establishing arbitration law. However, the situation of abuse in public policy was improved a lot by Chinese prime court which enforces pre-inspection system about judgment of rejection of enforcement in arbitral awards. So, there is no case about rejecting the approval and enforcement of arbitral awards by reason of violation in public policy by Chinese court except Yongning Co. case. Moreover, Chinese court got the trust and support from other countries through reinforcement of applied standard. However, Chinese court had been expressed concern from international society because they highly applied public policy and rejected to enforce arbitral awards in the recent case of Yongning Co.. Therefore, this study examined whether it is appropriate to apply public policy of Chinese court in the case of Yongning Co., and then I concluded that. Although Yongning Co. case is the first case which Chinese prime court agrees with public policy by reason of rejection of approval and enforcement in foreign arbitral awards, in my opinion, it doesn't mean that Chinese court has fundamental change in basic attitude and position about the approval and enforcement of foreign arbitral awards. Chinese court keeps the cautious uses of public policy in legal judgment of foreign arbitral awards and it looks like implementing the obligation in regulation of New York Convention sincerely.

• Journal of Chest Surgery
• /
• 제30권11호
• /
• pp.1055-1061
• /
• 1997

실험동물에서의 폐이식수술에서 비침습성 흉부전산화 단층 촬영을 이용하여 이식폐의 기능평가지표의 가치를 분석해 보고자 한국산 잡종견을 이용하여 좌측일측폐이식술후 7일 이상 생존시킨 성견을 대상으로 급성거부반응 및 허혈-재관류손상, 감염 등의 소견을 병리조직소견과 함께 관찰하였다. 실험견은 총 22마리에서 11마리씩 공급견과 수용견으로 나누어 시행하였다. 공급견의 심폐블록보존은 Modified Euro-Collins (MEC) 용액과 low potassium dextran glucose(UDG)용액을 이용하여 $10^{\circ}C에서$ 20시간 (1례에서 4시간 보존) 이상 냉장보관하였다 폐이식술후, 흉부 X-선과 연속적인 컴퓨터단층촬영을 수술 직후와 술후 3일 및 7일째 각각 시행하였다. 11례의 이식견 중 2례에서 급성거부반응을 보였고 전산화단층촬영상 폐침윤정도가 수술 직후 중등도였다가 수술 3일째 확장성으로 변하였다. 결론적으로 일측 폐이식성견의 실험적인 모델에서 이식폐장의 기능평가지표로서 컴퓨터단층촬영을 이용 하며 다른 평가지표와 유사한 소견을 얻었고 폐의 감염과 거부 반응의 구별은 단층촬영의 음영의 비교만으 로 감별이 용이하지 않았으며 다른 평가지표 및 폐생검\ulcorner 확인으로 조기거부반응의 진단 가능성을 평가할 수 있었다.

• 한국음향학회지
• /
• 제20권2호
• /
• pp.27-34
• /
• 2001

발화 검증이란 등록된 단어 목록 이외의 단어가 입력되었을 때, 미등록된 단어는 인식할 수 없는 단어임을 알려주는 기능으로써 사용자에게 친숙한 음성 인식 시스템을 설계하는데 중요한 기술이다. 본 논문에서는 가변어휘 단어 인식기에서 최소 검증 오류를 나타낼 수 있는 발화 검증 시스템의 알고리즘을 제안한다. 우선, 한국전자통신연구원의 PBW(Phonetically Balanced Words) 445DB를 이용하여 가변어휘 단어 인식에서의 미등록어 거절 성능을 향상시키는 효과적인 발화 검증 방법을 제안하였다. 구체적으로 특별한 훈련 과정이 없이도 유사 음소 집합을 많이 포함시킨 반음소 모델을 제안하여 최소 검증 오류를 지니도록 하였다. 또한, 음소 단위의 null hypothesis와 alternate hypothesis의 비를 이용한 음소 단위의 신뢰도는 null hypothesis로 정규화해서 강인한 발화 검증 성능을 보여 주었으며, 음소 단위의 신뢰도를 이용한 단어 단위의 신뢰도는 등록어와 미등록어 사이의 분별력을 잘 표현해 주었다. 이와 같이 새로이 제안된 반음소 모델과 발화 검증 방법을 사용했을 때, CA (Correctly Accept for Keyword: 등록어를 제대로 인정한 경우)는 약 89％, CR (Correctly Reject for OOV (Out-of-Vocabulary): 미등록어에 대해 거절한 경우)은 약 90％로써, 기존 필터 모델을 이용한 방법보다 미등록어 거절 성능이 ERR (Error Reduction Rate) 측면에서 약 15-21％ 향상됨을 알 수 있었다.

• 대한이식학회지
• /
• 제31권4호
• /
• pp.182-192
• /
• 2017

Background: In recent years, introduction of novel immunosuppressive agents and its proper implementation for clinical practice have contributed to improving clinical outcomes of kidney transplantation (KT). Here, we report clinical outcomes of KTs and related risk factors. Methods: From July 1998 to June 2016, 354 KTs (182 from living and 172 from deceased donors) have been performed at Ulsan University Hospital. We retrospectively reviewed the clinical characteristics and outcomes of KT recipients, then estimated graft and patient survival rate were estimated and analyzed risk factors using Cox-regression. Results: The median follow-up period was 53 months (range; 3 to 220 months). The mean ages of recipients and donors were 45.0 years (SD, 12.5) and 44.7 years (SD, 13.6) years, respectively. During follow-up, 18 grafts were lost and 5- and 10-year death-censored graft survival was 96.7% and 91.5%, respectively. Biopsy-proven acute rejection (BPAR) occurred in 71 patients (55 cases of acute cellular rejection and 16 of antibody-mediated rejection). Cox-regression analysis showed that BPAR was a risk factor related to graft loss (hazard ratio [HR], 14.38; 95% confidence interval [CI], 3.79 to 54.53; P<0.001). In addition, 15 patients died, and the 5- and 10-year patient survival was 97.2% and 91.9%, respectively. Age ≥60 years (HR, 6.03; 95% CI, 1.12 to 32.61; P=0.037) and diabetes (HR, 6.18; 95% CI, 1.35 to 28.22; P=0.019) were significantly related to patient survival. Conclusions: We experienced excellent clinical outcomes of KT in terms of graft failure and patient survival despite the relatively high proportion of deceased donors. Long-term and short-term clinical outcomes have improved in the last two decades.

• Membrane and Water Treatment
• /
• 제8권3호
• /
• pp.225-244
• /
• 2017

A novel thin-film nanocomposite (TFN) reverse osmosis (RO)/non-woven fabric (NWF) membrane was prepared by adding zinc oxide (ZnO) nanospheres ($30{\pm}10nm$) during the interfacial polymerization process of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on self-made polysulfone (PSF) membrane/polyester (PET) non-woven fabric support. The improved performance of TFN RO membrane was verified in terms of water contact angle (WCA), water flux, salt rejection, antifouling properties and chlorine resistance. The results showed that the WCA value of TFN RO surface had a continuous decrease with the increasing of ZnO content in MPD aqueous solution. The water flux of composite TFN RO membranes acquired a remarkable increase with a stable high solute rejection (94.5 %) in $1g{\cdot}L^{-1}$ NaCl aqueous solution under the optimized addition amount of ZnO (1 wt%). The continuous testing of membrane separation performance after the immersion in sodium hypochlorite solution indicated that the introduction of ZnO nanospheres also dramatically enhanced the antifouling properties and the chlorine resistance of composite RO membranes.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
• /
• pp.78-81
• /
• 2000

A new type low-pass filter design method based on a coupled line and transmission line theory is proposed to suppress harmonics by attenuation poles in the stop band The design formula are derived using the equivalent circuit of a coupled transmission line. The new low-pass filter structure is shown to have attractive properties such as compact size, wide stop band range and low insertion loss. The seventh-order low-pass filter designed by present method Ins a cutoff frequency of 0.9 GHz with a 0.01 dB ripple level. The coupled line type low-pass filter with stripline configuration was fabricated by using a high-temperature superconducting (HTS ; $YBa_2Cu_3O_{7-x}$) thin film on MgO(100) substrate. Since the HTS coupled line type low-pass filter was proposed with five attenuation poles in stop band such as 1.8, 2.5, 4, 5.5, 62 GHz. The fabricated low-pass filter has improved the attenuation characteristics up to seven times of the cutoff frequency Bemuse of good rejection of the spurious signals and harmonics, our low-pass filter is applicable to mobile base station systems such as cellular, personal communication systems and international mobile telecommunication(IMT)-2000 systems.

• 전자공학회논문지SC
• /
• 제47권3호
• /
• pp.40-47
• /
• 2010

본 연구는 심초음파에서 사용되는 실시간 심전도 QRS 검출성능 및 심전도 trigger 시간 지연 등의 생체신호측정모듈의 성능 개선을 확인하고자 하였다. 심초음파에서 사용되는 생체신호측정모듈의 심전도 QRS 검출에 대한 성능 평가 중에서 심전도 QRS 크기와 폭에 따른 검출성능, Tall T-wave 제거성능, 부정맥이 있는 심전도의 QRS 검출성능 및 Pacer pulse 검출성능은 심전도 국제 규격인 EC-13을 기준으로 성능을 비교 평가하였으며, QRS의 trigger 신호 지연 시간 및 기저선 복귀시간은 기존에 상용화되어 심초음파에 사용되고 있는 생체신호측정모듈의 성능과 비교 평가하였다. 본 연구에서는 위 4가지 항목은 국제규격인 EC-13 기준을 크게 만족하였으며, QRS의 trigger 신호 지연 시간은 심박수에 따라 17m~21ms 빠른 검출 결과를 보였으며 심전도 기저선 복귀시간도 1 beat 이상 빠른 결과를 보였다.

• 한국전자파학회논문지
• /
• 제22권3호
• /
• pp.275-281
• /
• 2011

본 논문에서는 UWB 통신을 위한 변형된 접지 면을 갖는 소형 평판형 모노폴 안테나를 제안하였다. 제안된 안테나는 UWB 통신에 적합한 초광대역 특성(3.1~10.6 GHz)을 만족하면서, 5 GHz WLAN 대역(5.15~5.35 GHz, 5.470~5.825 GHz)에 주파수 대역 저지 특성을 갖는다. 제안된 안테나는 접지 면에 두 개의 슬릿을 통해 임피던스 정합 특성을 향상시켰으며, 슬릿의 중앙으로부터 저지 대역의��${\lambda}$/4 길이를 갖는 두 개의 개방 스터브를 형성하여 주파수 대역 저지 특성을 유도하였다. 제작된 안테나는 저지 대역인 5.08~5.83 GHz를 제외하고, 2.88~10.83 GHz 대역에서 VSWR${\leq}$2를 만족한다.