고강도 콘크리트의 균열양상

이광명 대한토목학회 1994 대한토목학회 학술발표회 논문집 Vol.1994 No.1

수화열에 의한 매스 콘크리트의 온도상승에 영향을 미치는 인자에 관한 연구

이광명,신현목,김홍태 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.2

매스콘크리트 구조물에서는 초기재령시에 수화열에 의하여 온도상승이 유발되며 이때 내외부 온도차에 의하여 온도균열이 발생한다. 따라서 이러한 구조물의 건설 현장에서 발생하는 균열을 효과적으로 예방하기 위해서는 온도분포와 열응력의 예측이 매우 중요하다. 본 연구에서는 유한요소해석 프로그램을 이용하여 수화열에 의한 대형기초의 온도상승에 영향을 미치는 인자들에 대한 매개변수연구를 수행하였다 연구에서 고려한 인자는 골재의 종류, 열경계조건, 시멘트의 양, 콘크리트의 치기온도이었다. 결론적으로 효율적인 매스콘크리트의 온도균열제어대책을 수립하기 위해서는 이러한 요인들의 정도 및 경향에 대한 검토가 필요한 것으로 나타났다. In massive concrete structures the heat of hydration causes the temperature rise at early age of concrete and hence, thermal cracking may be occurred by temperature differentials between inside and outside of the structures. Therefore, the prediction of temperature distribution and thermal stress in concrete structures is very important to effectively control the cracks developed during their construction. In this paper, the parametric studies using finite element analysis program are performed to investigate the major factors influencing the temperature rise of the large foundation due to the heat of hydration. The factors considered in this study include type of coarse aggregate, thermal boundary condition, amount of cement, and temparature of fresh concrete. It is concluded that the effects of these factors should be examined to establish efficient control methods for the crack control of mass concrete structures.

A comparison of different gingival depigmentation techniques: ablation by erbium:yttrium-aluminum-garnet laser and abrasion by rotary instruments

이광명,이동열,신승일,권영혁,정종혁,허익 대한치주과학회 2011 Journal of Periodontal & Implant Science Vol.41 No.4

Purpose: The aim of this study is to compare two different gingival depigmentation techniques using an erbium:yttrium-aluminum-garnet (Er:YAG) laser and rotary instruments. Methods: Two patients with melanin pigmentation of gingiva were treated with different gingival depigmentation techniques. Ablation of the gingiva by Er:YAG laser was performed on the right side, and abrasion with a rotary round bur on the opposite side. Results: The patients were satisfied with the esthetically significant improvement with each method. However, some pigment still remained on the marginal gingival and papilla. The visual analog scale did not yield much difference between the two methods, with slightly more pain on the Er:YAG laser treated site. Conclusions: The results of these cases suggest that ablation of the gingiva by an Er:YAG laser and abrasion with a rotary round bur is good enough to achieve esthetic satisfaction and fair wound healing without infection or severe pain. Prudent care about the gingival condition, such as the gingival thickness and degree of pigmentation along with appropriate assessment is needed in ablation by the Er:YAG laser procedure. Purpose: The aim of this study is to compare two different gingival depigmentation techniques using an erbium:yttrium-aluminum-garnet (Er:YAG) laser and rotary instruments. Methods: Two patients with melanin pigmentation of gingiva were treated with different gingival depigmentation techniques. Ablation of the gingiva by Er:YAG laser was performed on the right side, and abrasion with a rotary round bur on the opposite side. Results: The patients were satisfied with the esthetically significant improvement with each method. However, some pigment still remained on the marginal gingival and papilla. The visual analog scale did not yield much difference between the two methods, with slightly more pain on the Er:YAG laser treated site. Conclusions: The results of these cases suggest that ablation of the gingiva by an Er:YAG laser and abrasion with a rotary round bur is good enough to achieve esthetic satisfaction and fair wound healing without infection or severe pain. Prudent care about the gingival condition, such as the gingival thickness and degree of pigmentation along with appropriate assessment is needed in ablation by the Er:YAG laser procedure.

골판지포장의 소재$\cdot$형태 변호시대 개막

이광명 한국골판지포장공업협동조합 1994 골板紙包裝ㆍ物流 Vol.1 No.2

“阳安布” 小议

이광명 단국대학교 동양학연구원 2022 東洋學 Vol.- No.87

Among the bronze coins of the Warring States Period unearthed in Hebei, Beijing-Tianjin area, Inner Mongolia, Liaoning, and the northern part of the Korean Peninsula, there is a two-character spade-shaped coin with the money text “Yang” on the left and “An” on the right. Whether from the shape of the coin or the calligraphy of the text, there are some differences on the spade-shaped coin between the states of Han, Wei, Zhao and Yan state. This discussion is focus on the spade-shaped coins of Yan state. The controversy is the texts on the coin should be called Yangan or Anyang. This paper points out that the proof for calling this type of spade-shaped currency “Anyang” is not sufficient,through the comparison of the geographical position, the research on the reading order of the texts, and the discussion on which the coin belongs to. Based on the archaeological excavated data, combined with the analysis and research, it is considered that the coin should be called “Yangan Bi”. This conclusion provided a very important clue for the study of the economic development of the State of Yan during the Warring States Period, as well as the administrative establishment of this area, and it is also of great significance for the study on the expansion and reign of the State of Yan to the Northeast of China. 出土于河北、京津地区、内蒙古、辽宁、韩半岛北部地区的战国时期青铜货币当中,有一种钱文左为 “阳”,右为 “安” 的双字布币。此类布币的国别有 “三晋” 布币与燕布之分。“三晋” 布币多为三孔方足布, 从器形和钱文书法来看, 燕国布币均有别于 “三晋” 布币, 本稿仅针对该类燕国布币作一探讨。目前对于 该类布币存在着到底为 “安阳” 布, 还是 “阳安” 布的争议。 本稿通过对地望问题的比较、钱文读序问题的考论、国别定性问题的探讨等, 指出以往将该类布币称为 “安阳” 布的依据并不充分, 较为牵强。并以考古发掘出土的客观实物资料为基础, 结合具体的分析与考 辩, 认为将之称为 “阳安” 布是较为妥当的。这对于研究战国时期燕国的经济发展, 以及对于这一地区的 行政建置等问题, 是非常重要的线索, 对于燕国向东北地区的扩展及统治研究也具有极为重要的意义。

콘크리트 구조물의 내구성 설계

이광명 한국콘크리트학회 1998 콘크리트학회지 Vol.10 No.2

콘크리트의 계면 파괴와 균열 전파 : 파괴규준과 수치모의

이광명 한국콘크리트학회 1996 콘크리트학회지 Vol.8 No.6

콘크리트의 역학적거동은 다양한 종류의 균열의 발생과 전파에 의하여 영향을 받는다. 최근 고성능 콘크리트의 개발이 이루어지면서 계면파괴와 계면역에서의 균열양상에 대한 연구가 중요한 분야로 부각되고 있다. 탄성이며 균질한 재료에 적용되는 균열전파에 대한 규준은 계면역에서 균열이 진전하는 경우는 유효하지 않으며 이 경우에는 콘크리트에서 균열전파를 예측하기 위하여 구성재료들의 파괴인성과 그들 사이 계면의 파괴인성의상대적인 크기를 고려하여야 한다. 본 논문에서는 계면균열선단에서 계면파괴역학변수인 에너지해방률과 하중위상각을 수치해석방법을 이용하여 구하는 방법과 계면에서의 균열전파의 예측을 위한 에너지해방률에 기초를 둔 파괴규준을 제안하였다. 계면역에서의 균열양상을 조사하기 위하여 계면균열을 가진 이상복합모델에 대한 실험과 수치해석연구를 수행하였으며 대체적으로 실험결과와 규준을 이용하여 예측한 결과가 서로 일치하는 결과를 얻었다. The mechanical behavior ot concrete is strongly influenced by various scenarios of crack initiation and crack propagation. Recently. the study of the interface fracture and cracking in interfacial regions is emerged as an important field, in the context of the developement of high performance concrete composites. The crack path criterion for elastically homogeneous materials is not valid when the crack advances at an interface because. in this case, the consideration of the relative magnitudes of the fracture toughnesses between the constituent materials and the interface are involved. In this paper, a numerical method is presented to obtain the values of two interfacial fracture parameters such as the energy release rate and the phase angle at the tip of an existing interface crack. Criteria based on energy release rate concepts are suggested for the prediction of crack growth at the interfaces and an hybrid experimental-numerical study is presented on the two-phase beam composite models containing interface cracks to investigate the cracking scenarios in interfacial regions. In general, good agreement between the experimental results and the prediction from the criteria is obtained.

2002년도 제1회 fib 회의

이광명,신현목 한국콘크리트학회 2002 콘크리트학회지 Vol.14 No.6

음악교육의 문제점과 개선방안

이광명 건국대학교 1979 師大論叢 Vol.2 No.1

토목 프로젝트 관리를 위한 BIM 기반 CPLM 시스템 개발

이광명,이창우,한송이,강형석,노상도,Lee, Kwang-Myong,Lee, Chang-Woo,Han, Song-Yi,Kang, Hyoung-Seok,Noh, Sang-Do 한국BIM학회 2011 KIBIM Magazine Vol.1 No.2

BIM technology, based on 3D model of civil engineering structures, creates and manages information of the structures throughout four stages: Planning, design, construction, and maintenance. BIM is now used around the globe for improvement of the construction productivity. However, in order to expect the efficient engineering work, collaboration system between participants in a construction project is necessary. Therefore, in this paper BIM based CPLM (Construction project lifecycle management) system was designed and developed by analyzing the requirements of participants of a construction project. CPLM system offers an environment which enables the sharing and management of information according to the each stage of construction. CPLM is expected to aid cooperative decision-making during the overall construction process through the process innovation and the efficient data management. BIM (Building Information Modeling)은 토목 구조물의 3차원 객체모델을 기반으로 기획 단계부터 설계, 시공 및 유지보수 단계에 이르기까지 대상 구조물에 관련된 모든 정보를 통합적으로 생성, 관리하는 기술이다. 현재 국내외의 다양한 건설 산업 분야에서는 건설 생산성 향상을 위하여 BIM 기술을 도입하여 활용하고 있다. 그러나 이러한 BIM 기술을 적용하여 효율적인 엔지니어링 업무를 수행하기 위해서는 무엇보다 참여 주체간의 협업 시스템이 필요하다. 따라서 본 논문에서는 토목 프로젝트 참여 주체의 요구사항을 분석하여 건설 프로젝트 관리를 위한 BIM 기반의 CPLM (Construction Project Lifecycle Management) 시스템을 설계, 개발하였다. CPLM 시스템은 건설 프로세스 단계에 따른 정보의 관리와 공유가 가능한 환경을 제공한다. 향후 CPLM 시스템을 실무에 도입함으로써 기존의 업무 프로세스를 개선하고 데이터를 효율적으로 관리할 수 있게 되어 의사결정에 도움을 줄 수 있을 것으로 기대된다.