• 한국구조물진단유지관리공학회 논문집
• /
• 제19권6호
• /
• pp.80-87
• /
• 2015

본 연구에서는 칼슘알루미네이트 시멘트(CAC) 모르타르의 수화생성물, 강도, 흡수율, 표면전기 저항성 및 염소이온 침투저항성을 실험적으로 고찰하였다. CAC 모르타르의 성능은 보통포틀랜드 시멘트(OPC) 모르타르의 성능과 상호 비교되었다. 실험 결과에 따르면, CAC 모르타르의 주요 수화생성물은 $C_2AH_8$ 및 $CAH_{10}$으로 조사되었으며, 압축 및 부착강도는 OPC 모르타르에 비하여 우수하게 나타났다. 뿐만 아니라, 표면전기 저항성 및 염소이온 침투저항성도 대체적으로 좋은 결과를 나타냄으로서, CAC의 우수한 성능도 확인하였다. 그러나, CAC 모르타르의 흡수율은 초기재령부터 OPC 모르타르에 비하여 다소 크게 나타남으로써, CAC 경화체의 표면흡수 성능을 개선하기 위한 연구가 더 필요할 것으로 판단된다. 반면, CAC 및 OPC 혼용배합 모르타르의 역학적 성능은 CAC 모르타르에 비하여 대체적으로 다소 떨어지는 것으로 조사됨으로써, CAC계 경화체 제조시 주의가 요구된다.

• Journal of Cardiovascular Imaging
• /
• 제31권1호
• /
• pp.1-17
• /
• 2023

The Coronary Artery Calcium Data and Reporting System (CAC-DRS) is a standardized reporting method for calcium scoring on computed tomography. CAC-DRS is applied on a per-patient basis and represents the total calcium score with the number of vessels involved. There are 4 risk categories ranging from CAC-DRS 0 to CAC-DRS 3. CAC-DRS also provides risk prediction and treatment recommendations for each category. The main strengths of CAC-DRS include a detailed and meaningful representation of CAC, improved communication between physicians, risk stratification, appropriate treatment recommendations, and uniform data collection, which provides a framework for education and research. The major limitations of CAC-DRS include a few missing components, an overly simple visual approach without any standard reference, and treatment recommendations lacking a basis in clinical trials. This consistent yet straightforward method has the potential to systemize CAC scoring in both gated and non-gated scans.

• 공학교육연구
• /
• 제19권4호
• /
• pp.24-34
• /
• 2016

There's been few research to study the effects of CAC(Computing Accreditation Committee) evaluation, since start of CAC accreditation 10 years ago. The purpose of this paper is to find what computer engineering graduates perceive the effects of CAC accreditation and to suggest how CAC accreditation process can be improved. The research findings through survey are followings; First, computer engineering graduates' undergraduate education satisfaction is not high enough(3.28). Second, the computer engineering graduates don't recognize CAC accreditation necessary. Third, graduates who work in company chose design courses as the most helpful, while graduates who study in graduate school pursuing further career in master or doctor program chose major subjects. Lastly, graduates from accredited program do not think their completion of accreditation program influence their employment. Strategic approaches to make higher effectiveness of CAC accreditation system are suggested. First, improvement of curriculum and instruction method in CAC accredited program is required to satisfy the needs of students and industry. Second, efforts to inform students of understandings and necessity of accreditation are highly recommended. Third, industrial sector needs to understand CAC accreditation and give graduates from accredited program more incentives. Lastly, government support like Seoul Accord Activation Project should last for a while.

• 전자공학회논문지S
• /
• 제35S권3호
• /
• pp.1-8
• /
• 1998

In this paper, we propose a Neural Call Admission Control (CAC) method using a Sparse Distributed Memory(SDM). CAC is a key technology of TM network traffic control. It should be adaptable to the rapid and various changes of the ATM network environment. conventional approach to the ATM CAC requires network analysis in all cases. So, the optimal implementation is said to be very difficult. Therefore, neural approach have recently been employed. However, it does not mett the adaptability requirements. because it requires additional learning data tables and learning phase during CAC operation. We have proposed a neural network CAC method based on SDM that is more actural than conventioal approach to apply it to CAC. We compared it with previous neural network CAC method. It provides CAC with good adaptability to manage changes. Experimenatal results show that it has rapid adaptability and stability without additional learning table or learning phase.

• 한국식품영양과학회지
• /
• 제35권8호
• /
• pp.973-978
• /
• 2006

동결건조한 chitosan-ascorbate(CAs)와 chitosan-acetate(CAc)의 용해성, 항균성, 항산화성을 비교하였다. 용해성을 조사한 결과 CAs는 증류수, 식초, 녹차, 소주, 맥주, 적포도주에 0.5%이상의 농도로 용해되었으나 간장, 두유, 우유, 오렌지주스, 커피, 참기름, 대두유에는 녹지 않았다. CAc도 CAs의 경우와 비슷하나 맥주에서는 0.1%이하의 농도에서 용해되었으며 적포도주에서는 커드를 형성하였다. CAc의 전자공여능, 항산화능 및 SOD활성은 CAc에서는 각각 0, 40.0 및 10.0%였으나 CAs의 경우는 48.2, 90.6 및 67.5%로 CAc보다 높은 활성을 나타내었다. B. circulans, B. brevis, B. licheniformis, B. arabitane, B. sterothermophillus에 대한 CAs와 CAc의 최소저해농도(MIC)는 다같이 $200\;{\mu}g/disc$이었으며, E. coli O157, Listeria monocytogenous, B. cereus, B. subtilis에 대한 MIC는 다같이 $400\;{\mu}g/disc$으로 뚜렷한 차이를 보이지 않았다. CAs와 CAc의 Hunter's L*값은 $81.95{\sim}82.97$로 뚜렷한 차이가 없었으나 Hunter's a* 및 b*값은 CAs가 높았다. 관능검사 결과, CAs는 CAc에 비하여 신맛과 쓴맛은 낮았으나 떫은맛은 뚜렷한 차이가 없었다. 결론적으로 CAs는 CAc에 비하여 항균성, 항산화성 및 기호도 측면에서 우수하여 식품에의 활용이 기대된다.

• 한국지역사회생활과학회지
• /
• 제18권4호
• /
• pp.699-706
• /
• 2007

The importance of the standards and its related texts established by Codex Alimentarius Commission (CAC) had been increased by the Agreement of Application of Sanitary and Phytosanitary Measures (SPS Agreement) in World Trade Organization (WTO). To meet the needs of WTO SPS Agreement, biennial CAC meeting had been changed to every year. This study was conducted to analyze the effects on interval between CAC meetings. The years of adoption, revision and amendment of CAC texts were collected from the official standard list and individual texts from CAC homepage. The period since establishment of CAC was divided into four groups by starting negotiation of Uruguay Round, WTO foundation and reducing the interval between CAC meetings. The collected data were analyzed by SPSS program. The numbers of CAC standards, guidelines, recommendations, maximum residue levels, and miscellaneous texts were 202, 56, 46, 3 and 5, respectively. Since 8 documents didn't contain the adoption year, these texts were eliminated to analyze adoption year. For adoption, annually 11.26 texts were established since establishment of CAC and there were no significant difference among the 4 groups. However the average numbers of revisions and amendments of adopted texts for overall periods and for each period were 7.56, 0.93, 6.50, 17.20 and 19.75, respectively. The average numbers of overall decisions, defined as summation of adoption, revision and amendment of texts, for overall periods and for each period were 12.37, 6.27, 9.00, 17.40 and 29.25, respectively. There were significant differences by the WTO foundation and the interval between CAC meetings. The reduced interval of CAC meetings influenced to increase number of revisions and amendments of adopted texts, but not yet adoption of new text.

• 공학교육연구
• /
• 제19권5호
• /
• pp.35-47
• /
• 2016

This study analyzed outcomes of CAC(Computing Accreditation Committee) program individually applied in the field of computing engineering since 2007, and draw improvements. Literature review through academic journals, survey research and the FGI(Focus Group Interview) were used to accomplish objectives of the study. In addition, the survey research and FGI were done for professors. For the survey research, nationally 20 out of 44 universities which operates the CAC program were investigated, and sample universities were considered by region. FGI was done to analyze the performance and problems of CAC in more detail for 6 experts. Results of the study were follows as; first, CAC program was activated through the Seoul Accord activation support business by government. Second, BSM(Basic Science and Math), engineering major and engineering design education have been strengthened compared with before and after of CAC introduction in the computing engineering field. Third, soft skills needed for students in the college of engineering have been organized in the professional general curriculum, and professors aware of improvement of ability of the students for the skills. The degree of satisfaction for the CAC program has been examined as normal level, but improvement of educational system and the overall quality enhancement of computing engineering education were affected by CAC program. Nonetheless of positive results of CAC program, incentive system for certification program graduates, the expansion of the autonomy of the department, reduction in the amount of self-evaluation report, and support of administrative human resources were suggested for taking root successfully of CAC program.

• 한국안전학회지
• /
• 제27권4호
• /
• pp.68-75
• /
• 2012

The biogenic corrosion of mortars adopted in sewage repair by sulfuric acid-producing bacteria was considered in this paper. Calcium aluminate cement (CAC) was known to resist microbiologically-induced corrosion significantly better than portland and blended portland cement.In this study, CAC as well portland cement mortars were tested as main binder to evaluate the corrosion resistance by the chemical immersion test. Replacement ratios of CAC were changed as 0, 20, 40, 50, 60% of OPC binder and 0, 2, 4, 6% of EVA(Ethylene Vinyl Acetate) were also adopted to increase properties of CAC repair mortars in sewage application. Setting time, compressive strength, acid resistance and adhesive strength were measured for various experiments. As a results of the experiments, the proper formulation of repair mortars was found at 40% of CAC and 4% of EVA. Finally, the CAC mortars adopted in field sewer pipe and were demonstrated to superior in adhesion and workability.

• 한국콘텐츠학회논문지
• /
• 제12권4호
• /
• pp.69-75
• /
• 2012

본 논문에서는 다양한 서비스의 QoS를 제공하기 위하여 호 수락 제어(Call Admission Control : CAC) 알고리즘에 트래픽 혼잡비를 적용했을 때 평균 데이터 전송율과 평균 패킷 지연시간을 비교 평가하였다. 우선권 기반의 트래픽 혼합비가 1:1:4:4일 때 호 수락 제어 알고리즘을 적용하지 않았을 경우 FTP 서비스는 0.4일 때, 웹 서비스는 0.6일 때, 스트리밍 서비스는 0.7일 때 패킷 지연 요구사항을 만족하지 못하는 것과는 달리 제안하는 호 수락 제어 알고리즘을 적용하였을 경우 성능 평가를 수행한 모든 도착률에 대해 모든 서비스의 패킷지연을 만족함을 보였다. 또한 WWW, FTP, Video, VoIP 서비스를 대상으로 호 수락 제어 알고리즘을 적용하여 트래픽 혼합비 환경에서 서비스의 QoS를 보장할 수 있음을 확인하였다.

• Korean Journal of Radiology
• /
• 제22권11호
• /
• pp.1764-1776
• /
• 2021

Objective: This study aimed to validate a deep learning-based fully automatic calcium scoring (coronary artery calcium [CAC]_auto) system using previously published cardiac computed tomography (CT) cohort data with the manually segmented coronary calcium scoring (CAC_hand) system as the reference standard. Materials and Methods: We developed the CAC_auto system using 100 co-registered, non-enhanced and contrast-enhanced CT scans. For the validation of the CAC_auto system, three previously published CT cohorts (n = 2985) were chosen to represent different clinical scenarios (i.e., 2647 asymptomatic, 220 symptomatic, 118 valve disease) and four CT models. The performance of the CAC_auto system in detecting coronary calcium was determined. The reliability of the system in measuring the Agatston score as compared with CAC_hand was also evaluated per vessel and per patient using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. The agreement between CAC_auto and CAC_hand based on the cardiovascular risk stratification categories (Agatston score: 0, 1-10, 11-100, 101-400, > 400) was evaluated. Results: In 2985 patients, 6218 coronary calcium lesions were identified using CAC_hand. The per-lesion sensitivity and false-positive rate of the CAC_auto system in detecting coronary calcium were 93.3% (5800 of 6218) and 0.11 false-positive lesions per patient, respectively. The CAC_auto system, in measuring the Agatston score, yielded ICCs of 0.99 for all the vessels (left main 0.91, left anterior descending 0.99, left circumflex 0.96, right coronary 0.99). The limits of agreement between CAC_auto and CAC_hand were 1.6 ± 52.2. The linearly weighted kappa value for the Agatston score categorization was 0.94. The main causes of false-positive results were image noise (29.1%, 97/333 lesions), aortic wall calcification (25.5%, 85/333 lesions), and pericardial calcification (24.3%, 81/333 lesions). Conclusion: The atlas-based CAC_auto empowered by deep learning provided accurate calcium score measurement as compared with manual method and risk category classification, which could potentially streamline CAC imaging workflows.