• 제목/요약/키워드: SRD

검색결과 62건 처리시간 0.031초

FeAPSO-34재료의 합성과 메탄올 전환에 놓인 촉매적 성능 (Synthesis of FeAPSO-34 Materials and Their Catalytic Performance on Methanol Conversion)

  • 엄명헌;강미숙
    • 한국재료학회지
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    • 제9권8호
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    • pp.798-803
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    • 1999
  • 본 연구는 SAPO-34 결정골격에 도입된 Fe(III)의 메탄올 전환성능에 미치는 영향에 중점을 두었다. 신속결정화법에 의해 높은 결정화도, 좁은 입자 분포도를 갖는 결정(FeAPSO-34; Si/Fe=40,20,5)들이 얻어졌으며, SRD와 SEM의 결과로부터, 골격에 도입된 Fe양이 증가할수록 결정화도는 감소하고, 그 입자크기도 아울러 감소함이 관찰되었다. 한편, 이들의 산성도는 골격에 도입된 Fe양이 증가할수록 감소하였고, 그 결과 메탄올 전환에 있어서 에틸렌의 선택성이 향상되는 결과를 가져왔다.

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낮은 위상 잡음의 B-WLL 대역 주파수 합성기의 설계 (Design of Low Noise Frequency Synthesizer for B-WLL RF Tranceiver)

  • 송인찬;고원준;한동엽;황희용;윤상원;장익수
    • 한국전자파학회논문지
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    • 제11권6호
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    • pp.959-968
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    • 2000
  • 본 논문에서는 낮은 위상 잡음을 갖는 B-WLL대역 국부발진기(LO)로 사용될 주파수 합성기를 설계 및 제작하였다. 2GHz 대역의 주파수 합성기를 구성, 낮은 위상잡음의 안정된 파형을 얻은 후 SRD(Step Recovery Diode)를 이용하여 주파수 체배기를 거쳐 12GHz 대역의 위상 고정된 안정된 신호를 얻었다. 제작된 주파수 합성기는 각각 출력 주파수 24.92 GHz, 25.10GHz, 25.26GHz를 가지며, 이 중 출력 주파수 24.92 GHz에서 0.44 dB의 발전출력과 -87.93 dB/Hz(@10KHz), -109,54dBc/Hz(@100 KHz)의 위상잡음 특성을 나타내었다.

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북경, 동경, 서울 소재 체인 음식점에서의 문화 차이에 따른 고객 인식 비교 연구 (Cross-Cultural Comparisons of Customer Perception at Restaurant Franchises in Beijing, Tokyo, and Seoul)

  • 최필성;라우 패트릭;전기철
    • 대한산업공학회지
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    • 제39권4호
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    • pp.239-246
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    • 2013
  • Global restaurant franchises are becoming more and more popular in China, Japan, and South Korea. Understanding target customers' needs for restaurant franchises is considered one of the most important factors for their business success. In this study, four domains-food-related domain (FRD), interior-related domain (IRD), staff-related domain (SRD), and convenience-related domain (CRD)-and 24 elements were classified. A survey with 450 respondents in the three capital cities (Beijing, Tokyo, and Seoul) was then conducted to examine the effect of the factors influencing customer satisfaction. After statistical analysis, thirteen main elements were found as factors influencing customer satisfaction. The analysis result showed that the food-related domain (FRD) was the most important in Beijing. The interior-related domain (IRD) and the convenience-related domain (CRD) were considered the most important in Tokyo and Seoul. Some cultural differences in customer satisfaction were also found. The results provide a guideline for better customer experience management of a restaurant franchise in the three cities.

전자전장비 개발에서 종합군수지원 요구사항의 효과적 관리를 위한 계층적 모델 (On a Hierarchical Model for Effectively Managing ILS Requirements of Electronic Warfare Equipments)

  • 김기백;이재천
    • 한국군사과학기술학회지
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    • 제13권5호
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    • pp.801-807
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    • 2010
  • Requirements management is one of the most essential activities of systems engineering in developing successful weapon systems. Particularly it is very important to consistently manage the traceability among the user requirements, the system requirements, the development specifications and the testing plans throughout the entire life cycle of the weapon system. However, the most part of requirements-related activities has centered around the functional and performance requirements but the integrated logistics support(ILS) requirement has not properly been managed. In this regard, a special attention is needed to develop and manage the ILS requirements. To do so, the ANSI/EIA-632 standard can be referred as a starting point since the ILS requirements of the weapon system under development are specified by the enabling products whereas the functional and performance requirements are covered by the end product requirements. Specifically, we first review and model several cases of previous weapon systems development, which reveals the problem of interest. Then, under the framework of ANSI/EIA-632, we study a hierarchical model for effectively managing ILS requirements by analyzing the features of ILS requirements. Finally, the value of the proposed model is discussed through the case study of electronic warfare equipment.

분만 여성의 산후 우울과 신체상의 관계 (Relationship Between Postpartum Depression and Body Image in Postpartum Women)

  • 김분한;전혜원;정연
    • 대한간호학회지
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    • 제32권6호
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    • pp.906-916
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    • 2002
  • The purpose of this study was to identify the change and difference and relationship of postpartum depression and physical image. Method: The subjects consisted of 86 postpartum women at one general hospital in Seoul. The data was collected from September to November 2001. The instrument used for this study were SRD (Self-Rating Depression Scale) and Norris' Body Image Scale to evaluate depression and body image. The collected data was analyzed with frequency, mean, t-test, paired t-test, ANOVA and Pearson's correlation coefficient. Result: The result of this study were as follows: 1. The mean score of D2 was significantly higher than D1(p=.003). There was no difference significantly B1 and B2(p=310). 2. There was significant correlation between the two, D1-D2(r=.381, p<.01), B1-B2(r=.364, p<.01), D1-B1(r=.579, p<.01), D2-B2(r= .567, p<.01). (*D1: depression of postpartum 1-3days, D2: depression of postpartum 6-8weeks, B1: body image of postpartum 1-3days, B2: body image of postpartum 6-8weeks) Conclusion: There was very high postpartum depression in postpartum women, but body image was positive. Also, there was correlated to postpartum depression and body image. Thus it is necessary to implement nursing intervention focused on to decrease the postpartum depression and to enhance the body image of the postpartum women.

FHSS 및 DSSS 방식 소출력 무선기기간 간섭 분석에 관한 연구 (A Study on Interference Analysis between FHSS and DSSS Short Range Radio Devices)

  • 김진영;김은철;양재수;류충상;오성택
    • 한국전자파학회논문지
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    • 제19권2호
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    • pp.271-279
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    • 2008
  • 본 논문에서는 FHSS 방식의 소출력 무선기기와 DSSS 방식의 소출력 무선기기가 동일 주파수 대역에 존재하는 경우 업무간 간섭을 분석하였다. 분석 방법은 몬테 카를로 방법을 이용하여 DSSS 방식의 소출력 무선기기의 불요 방사가 FHSS 방식의 소출력 무선기기에 미치는 영향을 간섭 확률 측면에서 계산하였다. 간섭 시뮬레이션은 DSSS 방식의 소출력 무선기기의 대역폭과 충격 계수에 따른 간섭량을 계산하였고, 전파 모델은 자유 공간으로 가정하였다. 그리고 간섭원과 피간섭원 사이의 거리에 따른 영향을 수신기에서의 BER 측면에서 분석하였다. 간섭 분석 결과, 간섭원의 대역폭보다는 충격 계수가 시스템 양립성에 많은 영향을 주는 것을 확인할 수 있었고, 단일 간섭원과 다중 간섭원이 존재하는 경우 BER 기준을 만족하는 이격 거리를 확인할 수 있었다.

침자기전(鍼刺機轉)의 중추신경계(中樞神經系)에서의 신경해부(神經解剖).생리학적(生理學的) 기초연구(基礎硏究) (A Neuroanatomical and Neurophsiolgical basic Study on the Mechanism of Acupuncture in central nervous system)

  • 김정헌
    • 한국한의학연구원논문집
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    • 제2권1호
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    • pp.514-550
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    • 1996
  • There are many theory in acupuncture mechanism, so we must know the detail contents. and then we can use the acupuncture as we know. the follow article will be helpful in this part. 1. Spinal cord are role in intermediate part in somatosensorypathway also in acupuncture stumulating tract 2. Acute pain pathway started in laminae I, V of gray colmn, next are the spinothalamic tract(trigeminal spinothalamic tract in above neck part) and then go to the specific thalamic nucleus. but chronic pain in laminae II, III, VI, VII, next are spinoreticular tract(trigeminal spinoreticular tract in the neck part) and finally to the nonspecific thalamic nucleus. 3. Thalamus is very important area in somatosensory stimuation including acupuncture stumulating sensory also as a pain control center. but except this, there are Hypothalamus, Limbic system Cerebral cortex and Cerebellum as intermediator. as we Know hypothalamus is related to the emotional analgesic system with a limbic system. 4. A ${\delta$ fiber has relationship in Acute, sharp and initial pain, contrary this C fiber is related with Chronic, dull and last pain. 5. In Acupuncture mechanism of pain analgesia, there are two theory, one is gate control theory as large fiber another is stimuation produced analgesia as small diameter fier. 6. In DNIC, the stimulation sources are mechanical, thermal, heating, pain and acupuncture stimulation etc. we call these as a Heterotopic Noxious Stimulation. 7. In DNIC, SRD(Subnucleus reticularis dorsalis)is core nucleus in pain imtermediated analgesic mechanism. 8. Takeshige insisted nonacupuncture point dependent analgesic mechanism and acupuncture point dependent analgesic mechanism. and protested that Stimulation acupuncture piing evoke blocking nomacupuncture point analgesic pathway.

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관상동맥질환 위험인자 유무 판단을 위한 심박변이도 매개변수 기반 심층 신경망의 성능 평가 (Performance Evaluation of Deep Neural Network (DNN) Based on HRV Parameters for Judgment of Risk Factors for Coronary Artery Disease)

  • 박성준;최승연;김영모
    • 대한의용생체공학회:의공학회지
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    • 제40권2호
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    • pp.62-67
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    • 2019
  • The purpose of this study was to evaluate the performance of deep neural network model in order to determine whether there is a risk factor for coronary artery disease based on the cardiac variation parameter. The study used unidentifiable 297 data to evaluate the performance of the model. Input data consists of heart rate parameters, which are SDNN (standard deviation of the N-N intervals), PSI (physical stress index), TP (total power), VLF (very low frequency), LF (low frequency), HF (high frequency), RMSSD (root mean square of successive difference) APEN (approximate entropy) and SRD (successive R-R interval difference), the age group and sex. Output data are divided into normal and patient groups, and the patient group consists of those diagnosed with diabetes, high blood pressure, and hyperlipidemia among the various risk factors that can cause coronary artery disease. Based on this, a binary classification model was applied using Deep Neural Network of deep learning techniques to classify normal and patient groups efficiently. To evaluate the effectiveness of the model used in this study, Kernel SVM (support vector machine), one of the classification models in machine learning, was compared and evaluated using same data. The results showed that the accuracy of the proposed deep neural network was train set 91.79% and test set 85.56% and the specificity was 87.04% and the sensitivity was 83.33% from the point of diagnosis. These results suggest that deep learning is more efficient when classifying these medical data because the train set accuracy in the deep neural network was 7.73% higher than the comparative model Kernel SVM.

3차원 Manifesto 기반 3D Point Cloud Data의 ROI 전송 지원 방안 (Supporting ROI transmission of 3D Point Cloud Data based on 3D Manifesto)

  • 임지헌;김준식;유성열;김회정;김상일;김규헌
    • 반도체디스플레이기술학회지
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    • 제17권4호
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    • pp.21-26
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    • 2018
  • Recently, the emergence of 3D cameras, 3D scanners and various cameras including Lidar is expected to be applied to applications such as AR, VR, and autonomous mobile vehicles that deal with 3D data. In Particular, the 3D point cloud data consisting of tens to hundreds of thousands of 3D points is rapidly increased in capacity compared with 2D data, Efficient encoding / decoding technology for smooth service within a limited bandwidth, and efficient service provision technology for differentiating the area of interest and the surrounding area are needed. In this paper, we propose a new quality parameter considering characteristics of 3D point cloud instead of quality change based on assumed video codec in MPEG V-PCC used in 3D point cloud compression, 3D Grid division method and representation for selectively transmitting 3D point clouds according to user's area of interest, and propose a new 3D Manifesto. By using the proposed technique, it is possible to generate more bitrate images, and it is confirmed that the efficiency of network, decoder, and renderer can be increased while selectively transmitting as needed.

북동 태평양 KODOS91-1지역퇴적환경 연구 (A Study on the sedimentological Environments in KODOS91-1 Area, Northeast Pacific)

  • 박정기;김기현
    • 한국해양학회지
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    • 제29권1호
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    • pp.17-27
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    • 1994
  • 한국심해연구(KODOS) 91-1지역에서 채취한 박스코어 퇴적물에 대해 미세립질 퇴적 물(2 um 이하)의 기원 및 각 광물의 분포경향과 미고생물 분석결과를 통해 퇴적환경 특성과 자생광물의 형성기작을 비교, 분석하였다. 점토광물에 대한 분석결과 퇴적물의 분포가 상대적으로 연령이 오래된 퇴적층(Unit II, III)으로 가면서 스멕타이트의 함 량은 증가하는 반면에 일라이트, 카오리나이트와 석영과 같은 육성기원퇴적물은 감소 하는 경향을 보였다. 또한, 미고생물에 대한 분석결과 상부퇴적층(Unit I과 Unit II상 부)에서는 제 3기와 제3기 방산층이 흔재되어 나타나는데 이는 퇴적물의 재동작용과 재분포가 매우 활발하였었다는 것을 의미하며, 퇴적층간에 산출되는 양상도 하부층으 로 가면서 퇴적물의 색도와 광물의 함량이 급격히 변화하는 뚜렷한 특징을 보여주고 있다. 퇴적층에 따른 퇴적물의 색도, 스텍타이트의 결정도와 미고생물자료를 비교한 결과 본 조사지역에서 나타나는 스멕타이트는 속성작용을 받아 형성된 자생기원의 광 물이 주로 분포하고 있음을 보여준다. 본 조사지역의 퇴적물에 나타나는 점토광물의 광물학적인 특성은 미고생물학적인 층서대비와 . 과거 지질시대를 통한 환경변이가 뚜 렷히 나타나며, 퇴적후 물리적인 기작과 지화학적인 영향에 의한 환경변화가 지속적으 로 활발하였음을 보여준다.

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