• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.3
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• pp.136-142
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• 2019

Nuclear power plant concrete structures are in contact with the coast, and durability due to chloride attack is very important because it is used as cooling water by taking seawater. For this purpose, a 3-year long-term saltwater immersion test was carried out to evaluate chloride ion diffusion coefficient and age apponent (m) The m values of the foundation with 4,000 class was 0.35 ~ 0.39, similar to KCI or ACI suggested values. essential service water constructions and tunnels of 5,000 class were 0.44 ~ 0.53 and 6,000 class, and 0.62 of reactor containment buildings were similar to the proposed values of FIB. As a result of the prediction of the service life with the measured age coefficient, all the safety related concrete structures of the nuclear power plants satisfied the service life of more than 60 years.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.324-333
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• 2018

The aim of this study was to investigate the latent classes and predictors of chronic diseases such as hypertension, dyslipidemia, arthritis, thyroid disease, depression, atopy, allergy, and diabetes. The subjects of this study were Korean citizens who participated in the Korea National Health and Nutrition Examination Survey in 2014. Stratified cluster sampling method was used with a sample size of 7,550. Latent hierarchy analysis was applied to this data. Four classes were identified. Class 1 consisted of participants with hypertension and diabetes. Class 2 consisted of participants with atopy and allergies. Class 3 consisted of participants with dyslipidemia, arthritis, thyroid disease, and depression. Class 4 consisted of participants without any chronic diseases. In comparing Class 1 to Class 4, age, physical activity, self-management, obesity, and presence of high cholesterol were found to be significant. In comparing Class 2 to Class 4, gender, age, and education level were significant. When Class 3 was compared to Class 4, gender, age, pain and discomfort, as well as high cholesterol were found to be significant. Diabetes and hypertension should be treated as comorbid conditions, applying integrated treatments involving effective drug treatment, diet, and physical activity programs. Atopy was found to be strongly correlated with allergies. Thyroid disease was found to coexist with dyslipidemia and arthritis, along with having a strong correlation to depression. Age-appropriate preventive measures can help reduce the risk of chronic diseases.

• Trans-
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• v.12
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• pp.51-79
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• 2022

This study investigates the methods for deriving colors which can serve as a reference to users such as designers and or contents creators who search for online images from the web portal sites using specific words for color planning and more. Two experiments were conducted in order to accomplish this. Digital scenery photos within the geographic scope of Korea were downloaded from web portal sites, and those photos were studied to find out what colors were used to describe daytime and nighttime. Machine learning was used as the study methodology to classify colors in daytime and nighttime, and KSCA was used to derive the color frequency of daytime and nighttime photos and to compare and analyze the two results. The results of classifying the colors of daytime and nighttime photos using machine learning show that, when classifying the colors by 51~100%, the area of daytime colors was approximately 2.45 times greater than that of nighttime colors. The colors of the daytime class were distributed by brightness with white as its center, while that of the nighttime class was distributed with black as its center. Colors that accounted for over 70% of the daytime class were 647, those over 70% of the nighttime class were 252, and the rest (31-69%) were 101. The number of colors in the middle area was low, while other colors were classified relatively clearly into day and night. The resulting color distributions in the daytime and nighttime classes were able to provide the borderline color values of the two classes that are classified by brightness. As a result of analyzing the frequency of digital photos using KSCA, colors around yellow were expressed in generally bright daytime photos, while colors around blue value were expressed in dark night photos. For frequency of daytime photos, colors on the upper 40% had low chroma, almost being achromatic. Also, colors that are close to white and black showed the highest frequency, indicating a large difference in brightness. Meanwhile, for colors with frequency from top 5 to 10, yellow green was expressed darkly, and navy blue was expressed brightly, partially composing a complex harmony. When examining the color band, various colors, brightness, and chroma including light blue, achromatic colors, and warm colors were shown, failing to compose a generally harmonious arrangement of colors. For the frequency of nighttime photos, colors in approximately the upper 50% are dark colors with a brightness value of 2 (Munsell signal). In comparison, the brightness of middle frequency (50-80%) is relatively higher (brightness values of 3-4), and the brightness difference of various colors was large in the lower 20%. Colors that are not cool colors could be found intermittently in the lower 8% of frequency. When examining the color band, there was a general harmonious arrangement of colors centered on navy blue. As the results of conducting the experiment using two methods in this study, machine learning could classify colors into two or more classes, and could evaluate how close an image was with certain colors to a certain class. This method cannot be used if an image cannot be classified into a certain class. The result of such color distribution would serve as a reference when determining how close a certain color is to one of the two classes when the color is used as a dominant color in the base or background color of a certain design. Also, when dividing the analyzed images into several classes, even colors that have not been used in the analyzed image can be determined to find out how close they are to a certain class according to the color distribution properties of each class. Nevertheless, the results cannot be used to find out whether a specific color was used in the class and by how much it was used. To investigate such an issue, frequency analysis was conducted using KSCA. The color frequency could be measured within the range of images used in the experiment. The resulting values of color distribution and frequency from this study would serve as references for color planning of digital design regarding natural scenery in the geographic scope of Korea. Also, the two experiments are meaningful attempts for searching the methods for deriving colors that can be a useful reference among numerous images for content creator users of the relevant field.

• Journal of Computing Science and Engineering
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• v.2 no.4
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• pp.412-427
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• 2008

We propose ID-exchange protocol for Connectionless Location-Awareness Service (CLAS) to locate mobile nodes in indoor sensor network. When adapting location-awareness service to sensor network, the target system must be designed in accordance with various metrics which reflect the system requirement. We especially consider sustainability of the existing service which has been provided for its original purpose, such as environmental monitoring. The detailed meaning of sustainability here is that, even if location-awareness service is newly added to the existing service, the system must be assured to retain a stable network condition, and to deal with newly caused traffic properly. The CLAS ID-exchange protocol is especially designed for fixture and mobile nodes communication to achieve these properties. The protocol operates on 802.15.4 MAC layer to make mobile node work independently of the procedure to build routing table of fixture node, so a stable routing condition can be achieved even if there are many mobile nodes. Moreover, the dedicated frequency channel is assigned only for this protocol, so that traffic caused by location-awareness service can be distributed to another channel. A real system adapting the protocol was implemented to monitor fire and authorities' positions. We verified the overhead and elapsed time for location-awareness. The result shows the proposed protocol has a high performance in detecting speed, traffic distribution, and stability of overall network.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.225-231
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• 2018

Recently, new teaching methods for communicating with teachers and students have been emerged according to the trends of decreasing the school-age population and the development of the mass media. We have applied teaching-learning model based on the flip learning to the college students in this work. As a result of the test for the customized flipped learning teaching-learning model in pre-class, the attendance rate of the major subject was 92.3% whereas that in liberal arts courses other than majors revealed 87.6%. This result for attendance rate shows that first year students in the radiology department have been actively participated in pre-class of the major subject than that of the liberal arts curriculum. From comparing the differences between the study group that was applied flipped learning in class and the non-applied group, the research group showed higher scores in knowledge, skills, and attitudes than the comparative group. In addition, more than 90% of the learners improved their responsibility, problem solving ability, creative thinking, cooperative ability, and communication ability through this learning program. From the test for the difference in the role of radiologists in the post class, the mean score was 4.40 for the group applied the teaching-learning model while that for non-applied group was 2.10. Hence, from such results, we see that this teaching-learning model is appropriate and needs to be extended to cultivate basic skills in radiology and relevant vocational education.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.366-371
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• 1993

This paper gives a convenient parameterization for the clas of all stabilizing controllers in the presence of plant perturbation. The perturbations are constrained in such class as plants are stabilizable by a nominal controller. By using the controller stabilizing a given plant with perturbation, we can obtain a parametrization of all stable closed-loop transfer functions, which are affine in the free parameter of the controller. It is easy to extend the controller to the case of a two-degree-of-freedom controller.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.219-222
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• 2000

일반적으로 WBI가 제공하는 시간과 장소를 초월하는 가상의 공간속에서 웹 환경에서 하이퍼미디어 기술을 도입하여 학습자가 학습에 대한 선택의 자유를 가지고 자기 나름대로 학습의 상황을 수시로 점검하고, 평가할 수 방법을 가지고 학습자가 학습에 대해 책임을 가지고 학습자 자신의 인지 구조를 최대한 반영하는 개별화 교수-학습 환경을 제공하고자한다. 개발된 Cyber Class는 LCPG 모델을 기반으로 하는 학습진행 및 학습평가 알고리즘을 제공하고 학습자 개개인의 특성에 맞는 재학습 메커니즘을 제공한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.96-99
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• 1996

본 연구는 CAD/CAM에서 3차원 물체를 표현하는 기법중 하나인 Solid Modeling을 구성하는 데이터 구조를 객체지향화 함으로써 보다 효율적이고 유연한 설계개발환경을 제공하고자 한다. 이를 위해서 가장 일반적으로 Solid Modeling을 표현하는 데이터 구조인 기존의 Half-Edge Data Structure를 기본모델로 하여 점(Vortex), 선(Edge), 면(Face), 입체(Solid)를 객체 Class로 하고 Euler Operator를 Method로 하는 객체지향 반모서리 데이터 구조(Object Oriented Half-Edge Data Structure)를 개발하였다.

• Proceedings of the Korean Society for Information Management Conference
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• 1994.12a
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• pp.79-82
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• 1994

본 연구에서 개발된 참고봉사 지원시스템은 도서관 안내정보시스템과 주제ㆍ토픽 전문가시스템으로 구성된다. 도서관 안내정보시스템은 도서관의 이용정보, 자료이용방법, 온라인목록의 사용방법 등에 관한 안내정보를 제공하는 시스템이다. 주제ㆍ토픽 전문가시스템은 정보사서가 가지고 있는 석유화학분야의 정보조사제공과 관련된 경험적 지식을 이용하여 관련 정보를 제공하는 전문가시스템이다. 본 연구에서 개발된 참고봉사 지원시스템은 IBM 호환기종의 개인용 컴퓨터(IBM PC AT 286 이상)에서 운영되며, 본 시스템의 개발언어로는 얘기보따리, 멀티미디어 메이커(Multimedia Maker), 1st-CLASS를 사용하였다.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.43-50
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• 2004

Diffserv Network DSCP(Differentiated Service Code Point)는 8bit로 구성되어 있고, 그 중 6bit만 사용되고, 나머지 2bit는 비워져 있는 상태로 있다. 이 2bit를 사용하여, DF(Default Forwarding), EF(Expedited Forwarding), AF(Assured Forwarding)의 DSCP 에 각각의 Service Class Code Point를 부여해서 사용자의 패킷을 구분하여 서비스하는 DiffServ 같은 경우 상용화가 되었을 때, DiffServ를 서비스하는 망에서 동일한 DiffServ 정책을 설정해서 사용할 수 있는 기법을 제안한다.