• 제목/요약/키워드: ThreeStep Process

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실험과 계산을 통한 에폭시 계열 내화도료의 열분해에 관한 연구 (Experimental and Numerical Study of the Thermal Decomposition of an Epoxy-based Intumescent Coating)

  • 김양균
    • 한국화재소방학회논문지
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    • 제30권1호
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    • pp.31-36
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    • 2016
  • 본 연구는 에폭시 계열 내화 도료의 열분해 특성을 파악하기 위해 열중량분석과 수치해석을 동시에 수행하였다. 에폭시 계열 내화 도료의 질량 감소 양상을 수치적으로 구현하기 위한 계산 모델이 소개되었으며, 계산 모델은 내화 도료의 여러 열분해과정을 단순화하여 4 단계의 순차적인 열분해 형태로 만들었다. 반응 속도는 Arrhenious 형태로 모델 되었고, 열중량분석을 통해 획득된 열분해 현상을 수치적으로 모사하기 위하여 화학 반응 매개변수들이 최적화되었다. 실험 결과 두 단계(two-step)와 세 단계(three-step)의 급격한 질량 감소가 질소와 공기 분위기에서 각각 나타났다. 또한 도료가 공기 분위기에 노출되었을 때 산소의 참여로 발생하는 복합적인 화학 반응들이 내화도료의 안정화를 도와 $200{\sim}500^{\circ}C$ 범위에서 질량 감소율을 낮추었다. 수치해석 결과는 실험과 비교하여 전체적으로 잘 일치하였으며 수치 모델에 포함되지 않은 $800^{\circ}C$ 이후를 제외하면 3% 미만의 오차를 보였다.

스텝 크기에 의한 CCA 적응 등화 알고리즘의 성능 평가 (A Performance Evaluation of the CCA Adaptive Equalization Algorithm by Step Size)

  • 임승각
    • 한국인터넷방송통신학회논문지
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    • 제19권3호
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    • pp.67-72
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    • 2019
  • 본 논문에서는 통신 채널에서 발생되는 찌그러짐의 영향을 최소화하기 위한 CCA 적응 등화 알고리즘에서 스텝 크기의 변화에 따른 성능을 해석하였다. CCA 알고리즘은 기존의 결정 지향 알고리즘 (DDA : Decision Directed Algorithm)과 축소 신호점 알고리즘 (RCA : Reduced Constellation Algorithm)의 적절한 결합 방식으로 송신 신호의 constant modulus와 결정 장치의 출력 신호를 compact slice 가중치만큼 고려하여 이들의 장점을 얻을 수 있다. 이 과정에서 compact slice 가중치를 고정시킨 후, 적응을 위한 알고리즘의 스텝 크기를 3가지로 변화시킬때의 성능을 컴퓨터 시뮬레이션을 통해 평가하였다. 시뮬레이션 결과 스텝 크기가 적을수록 수렴 속도는 늦지만 정상 상태 이후의 성능이 개선됨을 확인하였고, 특히 SER 성능에서는 스텝 크기가 적은 경우 robustness함을 알 수 있었다.

가족친화마을만들기를 위한 모델 및 핵심 요소 (A Discussion of the Family-Friendly Village Model and Important Factors)

  • 차성란
    • 가정과삶의질연구
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    • 제28권2호
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    • pp.63-76
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    • 2010
  • A law facilitating a family-friendly social environment was legislated in December 2007. According to the law, projects for facilitating a family-friendly social environment consisted of a family-friendly working environment, a community environment, and the promotion of a family-friendly culture. There has been much progress in developing a family-friendly working environment through projects such as those advocating for flexible work hours, an employee support system, and child care and a family care support system. However, in terms of a family-friendly community environment project, there was no noticeable advancement. Hence, this study was conducted to find ways to vitalize the family-friendly village project in terms of the family-friendly community environment project. The major findings of this study were as follows: A family-friendly village could be structured on the three axes of time, space, and relation. The model of the family-friendly village project consists of the following three steps: motivation, systematization, and participating & practicing. In the motivation step, integration, community, and sustainability were needed as basic ideologies for a family-friendly village. In the systematization step, providing systematic educational systems for residents taking on leadership and activist roles was stressed. In the participating & practicing step, many ways to facilitate residents' social relationships were suggested: starting the project from matters of common interests, making the resolution of families' problems a communal task of the residents, accepting the opinions of various groups associated with the matter, and taking a differentiated project process according to the geographic, socio-economic, and demographic characteristics of the groups. It is strongly suggested that the family-friendly village should be taken as a common functional scheme in everyone of eight livable village models because a key factor in a family-friendly village, family care, serves an essential function in any livable village model.

커튼월 공사에서의 단계별 컨설턴트 참여방안 연구 (A Study on Participation of Consultant in Curtain Wall Construction)

  • 윤형수;이동섭;구교진;현창택
    • 한국건설관리학회:학술대회논문집
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    • 한국건설관리학회 2003년도 학술대회지
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    • pp.618-621
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    • 2003
  • 이 연구의 목적은 현장 상황에 적절한 컨설턴트의 참여방안을 제안하는 것이다. 주의 깊게 고려된 컨설턴트의 참여는 공사비용과 기간을 단축시키고 공사 품질을 향상 시킬 수 있다. 연구의 첫 번째 단계는 커튼월 공사과정에 대한 문헌조사이다. 연구의 두 번째 단계는 공사에 관련된 전문가(설계자, 시공자. 전문시공업체, 컨설턴트)들에 대한 면담을 통한 커튼월 공사의 문제점을 분석하는 것이다. 이 때 우리는 컨설턴트가 이떻게 커튼일 공사의 문제를 해결할 수 있는지, 컨설턴트의 참여방안은 무엇인지 연구한다. 참여방안은 세 가지 방안으로 구성된다. 첫 번째 방안은 설계${\cdot}$시공단계 참여이고 두 번째 방안은 설계단계 참여, 참여, 세 번째 방안은 시공 단계 참여이다. 이러한 참여방안에 대한 검증은 전문가들의 면담을 통해 이루어졌다.

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코어-쉘 구조를 갖는 BaTiO3@Fe 나노섬유의 합성 및 전자파 흡수 특성 (Synthesis and Electromagnetic Wave Absorbing Property of BaTiO3@Fe Nanofibers with Core-Shell Structure)

  • 이영인;장대환;성기훈;이규만;좌용호
    • 한국분말재료학회지
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    • 제23권1호
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    • pp.38-42
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    • 2016
  • $BaTiO_3$-coated Fe nanofibers are synthesized via a three-step process. ${\alpha}-Fe_2O_3$ nanofibers with an average diameter of approximately 200 nm are first prepared using an electrospinning process followed by a calcination step. The $BaTiO_3$ coating layer on the nanofiber is formed by a sol-gel process, and a thermal reduction process is then applied to the core-shell nanofiber to selectively reduce the ${\alpha}-Fe_2O_3$ to Fe. The thickness of the $BaTiO_3$ shell is controlled by varying the reaction time. To evaluate the electromagnetic (EM) wave-absorbing abilities of the $BaTiO_3@Fe$ nanofiber, epoxy-based composites containing the nanofibers are fabricated. The composites show excellent EM wave absorption properties where the power loss increases to the high frequency region without any degradation. Our results demonstrate that the $BaTiO_3@Fe$ nanofibers obtained in this work are attractive candidates for electromagnetic wave absorption applications.

Automatic Generation of GCP Chips from High Resolution Images using SUSAN Algorithms

  • Um Yong-Jo;Kim Moon-Gyu;Kim Taejung;Cho Seong-Ik
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.220-223
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    • 2004
  • Automatic image registration is an essential element of remote sensing because remote sensing system generates enormous amount of data, which are multiple observations of the same features at different times and by different sensor. The general process of automatic image registration includes three steps: 1) The extraction of features to be used in the matching process, 2) the feature matching strategy and accurate matching process, 3) the resampling of the data based on the correspondence computed from matched feature. For step 2) and 3), we have developed an algorithms for automated registration of satellite images with RANSAC(Random Sample Consensus) in success. However, for step 1), There still remains human operation to generate GCP Chips, which is time consuming, laborious and expensive process. The main idea of this research is that we are able to automatically generate GCP chips with comer detection algorithms without GPS survey and human interventions if we have systematic corrected satellite image within adaptable positional accuracy. In this research, we use SUSAN(Smallest Univalue Segment Assimilating Nucleus) algorithm in order to detect the comer. SUSAN algorithm is known as the best robust algorithms for comer detection in the field of compute vision. However, there are so many comers in high-resolution images so that we need to reduce the comer points from SUSAN algorithms to overcome redundancy. In experiment, we automatically generate GCP chips from IKONOS images with geo level using SUSAN algorithms. Then we extract reference coordinate from IKONOS images and DEM data and filter the comer points using texture analysis. At last, we apply automatically collected GCP chips by proposed method and the GCP by operator to in-house automatic precision correction algorithms. The compared result will be presented to show the GCP quality.

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성남시 무료 노인 급식에서 제공되는 고구마줄기무침의 미생물학적 위해 분석 (Microbiological Hazard Analysis for Seasoned Sweet Potato Stems in a Free Meal service Operation for the Elderly in Sungnam)

  • 박지현;김혜영
    • 한국식품조리과학회지
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    • 제23권3호통권99호
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    • pp.378-387
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    • 2007
  • In this study, we investigated the application of HACCP for a prepared side dish of sweet potato stems, within a free meal service system for the elderly in the Sungnam area. Total bacterial counts (TBC) and levels of coliforms and Esherichia coli (E.coli) were analyzed through an eight step cooking process. The TBCs of the raw samples ranged between 3.30 and 1.37${\times}10^4$ CFU/g per 100 cm$^2$ The trimmed, blanched, and drained sweet potato stems showed a mean TBC value of 1.37${\times}10^4$ CFU/g, and the level of coliforms was 1.48${\times}10^3$ CFU/g. Among the eight samples, however, after stir-frying and serving, the TBC decreased to a standard satisfactory level, and a coliforms and E. coli were not found. A five step process was used and samples were taken to check the microbial quality of the cook and cooking equipment. Here we tested for TBC, coliforms, Staphylococcus aureus (S. aureus), and Salmonella. Specifically, the TBC and number of coliforms were examined on the cook's hand's, cutting board, and knife, as they represented hazards for cross-contamination. The three inspection steps of preparation of the trimmed, rinsed, blanched, and drained sweet potato stems, cook's' hands, cutting board and knife were all considered CCPs, and a manual of cooking process management was established to improve the risk factors in this study. In conclusion, this study reinforces that microbiological analysis is as a valuable tool for checking what points and stages of the cooking process must be controlled.

선제 대응을 위한 의심 도메인 추론 방안 (A Proactive Inference Method of Suspicious Domains)

  • 강병호;양지수;소재현;김창엽
    • 정보보호학회논문지
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    • 제26권2호
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    • pp.405-413
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    • 2016
  • 본 논문에서는 선제 대응을 위한 의심 도메인 추론 방안을 제시한다. TLD Zone 파일과 WHOIS 정보를 이용하여 의심 도메인을 추론하며, 후보 도메인 탐색, 기계 학습, 의심 도메인 집단 추론의 세 과정으로 구성되어 있다. 첫 번째 과정에서는 씨앗 도메인과 동일한 네임 서버와 업데이트 시간을 가진 다른 도메인을 TLD Zone 파일로부터 추출하여 후보 도메인을 형성하며, 두 번째 과정에서는 후보 도메인의 WHOIS 정보를 정량화하여 유사한 집단끼리 군집화 한다. 마지막 과정에서는 씨앗 도메인을 포함하는 클러스터에 속한 도메인을 의심 도메인 집단으로 추론한다. 실험에서는 .COM과 .NET의 TLD Zone 파일을 사용하였으며, 10개의 알려진 악성 도메인을 씨앗 도메인으로 이용하였다. 실험 결과, 제안하는 방안은 55개의 도메인을 의심 도메인으로 추론하였으며, 그 중 52개는 적중하였다. F1은 0.91을 기록하였으며, 정밀도는 0.95을 보였다. 본 논문에서 제안하는 방안을 통해 악성 도메인을 추론하여 사전에 차단할 수 있을 것으로 기대한다.

Facial Shape Recognition Using Self Organized Feature Map(SOFM)

  • Kim, Seung-Jae;Lee, Jung-Jae
    • International journal of advanced smart convergence
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    • 제8권4호
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    • pp.104-112
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    • 2019
  • This study proposed a robust detection algorithm. It detects face more stably with respect to changes in light and rotation forthe identification of a face shape. The proposed algorithm uses face shape asinput information in a single camera environment and divides only face area through preprocessing process. However, it is not easy to accurately recognize the face area that is sensitive to lighting changes and has a large degree of freedom, and the error range is large. In this paper, we separated the background and face area using the brightness difference of the two images to increase the recognition rate. The brightness difference between the two images means the difference between the images taken under the bright light and the images taken under the dark light. After separating only the face region, the face shape is recognized by using the self-organization feature map (SOFM) algorithm. SOFM first selects the first top neuron through the learning process. Second, the highest neuron is renewed by competing again between the highest neuron and neighboring neurons through the competition process. Third, the final top neuron is selected by repeating the learning process and the competition process. In addition, the competition will go through a three-step learning process to ensure that the top neurons are updated well among neurons. By using these SOFM neural network algorithms, we intend to implement a stable and robust real-time face shape recognition system in face shape recognition.

의류제품유형 및 성별에 따른 구매후 만족에 관한 연구 (A Study on the Post-purchase Satisfaction of Clothing related to Clothing Type and Sex)

  • 김지영;박재옥
    • 복식문화연구
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    • 제10권1호
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    • pp.49-59
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    • 2002
  • The type of product and consumer characteristis have known to play an important role in the post-purchase behavior. The issue related to the effects of clothing type and sex on the process of consumer satisfaction formation, would be helpful to understand the past-purchase consumer behavior. Therefore, the objective of this study was to clarify differences in the process of satisfaction formation in relation to clothing type and sex. The study was conducted in three steps. Through the two steps, measurement instruments were developed. At the last step, judgement sampling method was utilized to collect the data and subjects were 614 university students. Factor analysis and path analysis were used to analyze the data. The process of consumer satisfaction formation in formal wear and casual wear showed some differences. In the case of format wear, only expressive product performance was found to play an important role in the process of consumer satisfaction formation. However in the case of casual wear, both expressive and instrumental product performances had influence upon clothing satisfaction directly or through consumption emotion. The results revealed a similar tendency in the process of satisfaction formation between male and female groups. However in the male group the consumption emotion had a greater effect on the process of consumer satisfaction formation than in the female group it did.

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