• Computers and Concrete
• /
• 제11권3호
• /
• pp.223-236
• /
• 2013

Self-healing (SH) technology of cracking is becoming a promising solution to improve the durability of cement based composites. However, little formula are available in the literature on determining the size and dosage of the self-healing capsules. Supposed that SH capsules will be broken and activated when they met cracks, a theoretical solution is developed to calculate the appropriate length of SH capsules based on Buffon's needle model. Afterwards, a method to calculate the dosage of capsules was proposed in terms of stereological theory. The reliability of the above mentioned theoretical methods was verified by computer simulation. An experiment of self-healing in mortar was performed as well, by which the theoretical models were verified.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2022년도 가을 학술논문 발표대회
• /
• pp.253-254
• /
• 2022

In this study, as part of a study to improve the self-healing performance of concrete, the fluidity and strength characteristics of mortar mixed into cement composites were compared and analyzed by controlling the mixing rate of BSC(Bioinspired Self-Healing capsule)

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.321-322
• /
• 2023

This study compared the compressive strength and healing strength to confirm the self-healing performance of mortar incorporating Bioinspired Self-healing Capsule (BSC) into cement composites as part of a study to mitigate the problem of durability deterioration due to cracks in concrete structures. As a result of the evaluation, it was found that the healing performance decreased as the mixing ratio of the BSC capsule increased.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
• /
• pp.411-414
• /
• 2005

Concrete structure is recognized as the universal structuring material for its outstanding formability, economic efficiency, and strength development. However, as the ageing of field workers and the deficiency of skilled workers due to evasions from 3D business have recently become the major issues of the industry in Korea and as the materials are becoming more diversified and complicated for today's concrete structures are becoming higher, larger, and specialized, the need for practicality of construction work based on new technology and new method has greatly increased. In other words, the overall condition of today's construction business requires researches and developments on the self-compacting concrete for higher construction efficiency and quality improvements and the high-strength lightweight concrete for concrete weight reduction and reduction of area. Therefore experimental tests were performed as such compressive strength, dry shrinkage and carbonation of self-compacting concrete.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 춘계 학술발표회 논문집
• /
• pp.257-267
• /
• 2006

The earth retaining wall systems for excavation works in a populated urban area or a poor soil deposit can be limited due to various restriction. Thus there are various methods to be applied for them such as the soldier pile method, the diaphragm wall with counterfort and so on. In this study, the self-supported earth retaining wall using the DCM(Deep Cement Mixing) method, including its merits, demerits and some important characteristics occured in the design and the construction stage, was introduced. It might be reference for the other design and construction procedures using the DCM method.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
• /
• pp.325-326
• /
• 2012

Because steel frame has own characteristics as easy to work and structural safety, it is being increased application by the trend of construction industry has been more higher and larger in today. However, steel frame works have potential problem, so fundamental solution is needed for preventing serious accidents. Recently, self-supported steel joint for enhancing safety is developed in Korea, but this system has some limitations as convenience of work, retainment of consistent productivity. For complementing this limitations, we developed the new system named Automated wire control machine. This study is performed productivity of steel frame work by new system. The basis data for analysing productivity is collected from field test.

• 한국건축시공학회지
• /
• 제3권3호
• /
• pp.91-97
• /
• 2003

At present, the antiwashout underwater concretes are used as popular construction materials in European countries, the United States and Japan. The water-soluble polymers in the antiwashout underwater concretes provide excellent segregation or washout resistance, self-compaction and self-leveling property to the concretes. The purpose of this study is to recommend to optimum mix proportions of antiwashout underwater concretes according to compressive strength of 300kgf/$\textrm{cm}^2$ to 500kgf/$\textrm{cm}^2$. The antiwashout underwater concretes are prepared with various unit cement content, unit water content, sand-aggregate ratio, unit antiwashout agent and superplasticizer content. And they are tested for flowability, and compressive strength. From the test results, it is possible to recommend the optimum mix proportions of antiwashout underwater concretes according to compressive strengths within the range of 300kgf/$\textrm{cm}^2$ to 500kgf/$\textrm{cm}^2$.

• 한국전산구조공학회논문집
• /
• 제30권4호
• /
• pp.343-350
• /
• 2017

RC 플랫 플레이트 시스템은 공기단축, 시공성 향상, 층고 절감 등의 장점이 있으나, 장스팬 적용 시 슬래브의 작은 휨강성으로 인해 균열 손상 및 과다 처짐이 발생하는 경향이 있다. 특히, 시공 중 슬래브 자중에 의한 과하중의 작용이 슬래브의 장단기 처짐을 증가시킬 수 있다. 이러한 문제점은 자중 저감이라는 장점을 갖고 있는 중공 슬래의 사용을 통해 해결할 수 있다. 이 연구에서는 슬래브 처짐에 대한 중공 슬래브의 자중저감 효과를 분석하기 위하여 변수연구를 수행한다. 콘크리트 강도, 슬래브 시공주기, 동바리 지지층수, 압축철근비, 인장철근비 등의 변수조건들을 포함하여, 시공단계, 콘크리트 균열, 장기 효과를 고려한 시공하중 및 처짐을 산정한다. 일반 슬래브와 중공 슬래브에 대한 시공 중 단기처짐과 완공 후 장기처짐을 비교하고, 슬래브 처짐에 대한 중공 슬래브의 효과를 분석한다.

• 지역사회간호학회지
• /
• 제28권4호
• /
• pp.366-374
• /
• 2017

Purpose: The purpose of this study was to evaluate the validity and reliability of the Korean Version of the Nurses' Self-Concept Instrument (NSCI) geriatric hospital nurses in Korea. Methods: Bilingual nursing professionals performed translation and back-translation. Reliability and validity of the content and construction of the instrument were confirmed. Internal consistency reliability was determined. Construction and concurrent validity were verified using factor analysis and correlation coefficients. Results: The total 14 items for the Korean version of the Nurses' Self-Concept Instrument (NSCI) were retained through item analysis. In explanatory factor analysis, four subcategories were proposed with their names of each factor: 'Leadership', 'Staff relation', 'Knowledge', and 'Care'. The four factors accounted for 78.81% of the variances. The Cronbach's ${\alpha}$ regarding internal consistency were .77~.91 for the NSCI subscales. Correlation among four subcategories ranged .62~.84. Conclusion: The findings show that the Korean version of the Nurses' Self-Concept Instrument is reliable and valid for measuring professional Self-Concept of geriatric hospital nurses in Korea.

• 한국정보통신학회논문지
• /
• 제22권6호
• /
• pp.922-928
• /
• 2018

최근 서비스 지향 사물인터넷 네트워킹 기술에 관한 다양한 연구가 진행 중이다. 이는 사물인터넷 환경이 특정 통일 지역 내에 자신의 서비스를 제공하기 위한 다양한 서비스 디바이스들이 공존하기 때문이다. 따라서 이런 네트워크 환경은 네트워크 구성에 있어 효율적인 데이터 전달 서비스를 제공하지 못한다. 또한 이런 사물인터넷 네트워크 환경에서 효율적 서비스 제공 위해 스스로 서비스를 인지하고 서비스 별 네트워크 구성 기법이 필요하다. 따라서 본 논문에서는 다양한 서비스 디바이스로 구성된 사물인터넷 환경에서 서비스 중심 네트워크 구성이 가능한 서비스 중심 자율-구성 네트워크 (Service Oriented Self-Construction Network (SO-SCN) 기법을 제안한다. 제안하는 기법은 서비스 제공 시 필요한 네트워크 오버헤드의 최소화와 함께 네트워크 수명을 연장 할 수 있는 방법이다. 특히, 실험을 통해서 제안한 기법이 단대단 데이터 발생률과 단대단 지연 측면에서 제안하는 기법의 성능이 우수함을 증명하였다.