Analysis of safety risk factors to prevent accidents in modular construction

학위논문 (석사) -- 서울대학교 대학원 : 공과대학 건축학과, 2020. 8. 이현수.모듈러 건축은 대부분의 제작 공정이 공장에서 수행됨으로써 일반 건설에 비해 안전하다고 여겨진다. 하지만 모듈러 건축의 일반적인 인식과는 달리, 일부 연구와 산업 데이터에 따르면 모듈러 건축의 사고율이 전문가의 기대만큼 낮지 않다고 지적하고 있다. 이러한 부분은 모듈러 건축의 안전성에 의구심을 가져다 주며 안전관리가 필요하다는 것을 나타낸다. 모듈러 건축이 최근 떠오르는 산업으로 주목받고 있고, 많은 프로젝트가 수행되는 시점에서, 모듈러 건축에 적합한 안전관리가 필요한 것이다. 모듈러 건축의 안전을 향상시키기 위해서는 우선 안전 리스크 요인들을 분석하여야 한다. 또한 안전 사고를 사전에 예방하기 위해서 기존의 사고 사례를 분석하여 사고 유형 및 사고 원인을 파악하여야 한다. 이러한 문제를 해결하기 위하여, 먼저, 본 연구는 모듈러 건축과 관련된 사고 사례를 조사하고, 안전 리스크 요인들을 분석한다. 본 연구는 2000년부터 2018년 사이에 미국에서 발생한 사고 사례를 수집하고, 각 사고 사례의 사고 유형과 사고 원인 등의 안전 리스크 요인 분석을 실시한다. 분석은 모듈러 전체 프로세스를 제작과정과 시공과정으로 나누어 실시하고, 건설 관련 원인 인자를 사전에 분석하여 사고 원인 분석에 적용한다. 분석 결과는 표와 동시에 원인 맵을 생성하여 나타낸다. 분석 결과로부터 각각의 작업에 따른 주요 사고 유형 및 사고 원인을 확인할 수 있다. 결과를 바탕으로, 교차분석이라는 통계적 분석을 실시하는데, 이를 통하여 모듈러 건축의 작업 특성이 안전 사고와 연관성이 있음을 통계적으로 확인한다. 모듈러 건축의 분석 이후에 본 연구는 모듈러 건축과 일반건축의 사고 리스크 요인과 특성의 비교분석을 실시한다. 비교 분석을 통하여, 사고 요인들에 차이점과 모듈러 프로젝트를 위한 안전 관리가 필요하다는 것을 확인할 수 있다. 최종적으로 모듈러 건축에서의 안전사고의 추이를 확인하고, 안전사고를 예방할 수 있는 저감방안을 제시한다. 이를 바탕으로 모듈러 건축의 작업별 안전 체크리스트를 제시한다. 본 연구는 모듈러 건축의 제작과정과 시공과정에서의 안전관리 기초자료로 사용될 수 있다. 또한 연구 결과는 안전 관리자가 안전 위험 요인을 이해하고, 적절한 의사결정을 하는데 도움을 줄 수 있다.Modular Construction is regarded as having enhanced safety compared to traditional construction since most of modular manufacturing process is conducted in plants. Unlike general perception of safety in modular construction, several industrial accident data and researches have pointed out that the accident rate of modular construction is not enough less as much as the experts have expected. It means that there is a clear need for improvement of safety management in modular construction. Since the modular construction industry is drawing attention and many projects are being tried, safety management suitable for modular construction is essential. To enhance safety of modular construction, the safety risk factors should be identified first. It is necessary to identify types and causes of accident through accident cases in order to prevent safety accident in advance. To solve this problem, firstly, this study investigates accident cases related to modular construction and identifies safety risk factors. The study collects accident cases that occurred in the United states between 2000 to 2018 and analyzes safety risk factors such as types and causes of accidents with accident cases. The analysis is carried out by classifying the manufacturing process and the construction process, and the identification of casual factors is carried out in advance for the cause analysis. The analysis results are expressed in tables and cause map. The results of analysis show the major accident types and causes of accidents occurring in each activities. Secondly, this study compares safety risk factors and characteristics of accidents between general construction and modular construction. By comparative analysis, it is possible to identify differences in accident factors, and to confirm requirements of safety management in modular construction projects. Also, this study suggest prevention method to reduce safety accidents in modular construction project. Based on this, a safety checklist for each activities of modular architecture is presented. This study contributes that the result can be used as the basic safety management in the manufacturing and construction process of modular construction. Outcomes can also assist safety managers to understand safety risk factor and to make prompt safety decisions.Chapter 1. Introduction 1 1.1. Research Background 1 1.2. Problem Statement 5 1.3. Research Objective and Scope 7 1.4. Research Process 9 Chapter 2. Preliminary Study 11 2.1. Researches on Safety Management in Modular 11 2.2. Characteristics of Activities in Modular Construction 13 2.3. General Construction Safety Accident 18 Chapter 3. Accident Factor Analysis in Modular 20 3.1. Process of Analysis 20 3.2. Data Collecting 22 3.3. Identifying Casual Factors 24 3.4. Identifying Accident Cause 29 Chapter 4. Results of Accident Analysis 36 4.1. Hazardous Activities 37 4.2. Accident Types 39 4.3. Accident Causes 41 4.4. Summary 44 4.5. Relationship Analysis between Accident Factors 45 Chapter 5. Comparative Analysis with General Construction 48 5.1. Accident Type Ratio 50 5.2. Project Cost 52 5.3. Fall Location 53 5.4. Fall Height 55 Chapter 6. Discussion 56 6.1. Trends of Accidents in Modular Construction 56 6.2. Suggestions of Safety Management 57 6.3. Safety Checklist for Modular Construction 60 Chapter 7. Conclusion 67 Bibliography 69 Appendix 74 A. Web Crawling Code for Data Collecting 74 B. Samples of Accident Cases 77 C. Results of cross-tabulation analysis 79 D. Survey Form for Safety Checklist 83 Abstract in Korean 84Maste

(The)Emerging path and the method of full-length-novelization of the 17th century Korean novels

학위논문(박사)--서울대학교 대학원 :국어국문학과 국문학전공,2005.Docto

「折花奇談」硏究 : 19세기 愛情傳奇 傳統의 繼承과 變容

학위논문(석사)--서울대학교 대학원 :국어국문학과 국문학전공,1999.Maste

天機論의 문제

Cheon-ki-ron天機論 has been regarded as the representative criticism of poems in the late Joseon朝鮮 dynasty. Until now, it has been recognized that Cheon-ki-ron rose against Seong-jeong-ron性情論, the representative criticism of poems in the early Joseon dynasty. And we looked upon Cheon-ki-ron as a trial not only to be free from edification, but also to go to the affirmation of emotion and the discovery of individuality. But by researching of the typical statement about Cheon-ki-ron by Jang Yoo張維(1587~1638) & Kim Chang-hyeop金昌協(1651~1708) and about Seong-jeong-ron by Zhu Xi朱熹(1130~1200), I concluded that Cheon-ki-ron had no originality in comparison with Seong-jeong-ron. Therefore, I propose that we should reexamine the whole poetics built on the opposition between Seong-jeong-ron and Cheon-ki-ron. Investigating the viewpoint of establishing Cheon-ki-ron as the Joseon"s characteristic aesthetics, I found that the contents of Cheon-ki-ron were close to the synthesis of various theories of literary arts of East Asia in 16~17th century as well as the poetics of Chianhou-chizi前後七子. Accordingly, I concluded that Cheon-ki-ron was not the aesthetics native to Korea in the late Joseon dynasty

질량 및 바이오 센서에 응용 가능한 질화 티타늄을 이용한 고주파 나노 기계적 공진기에 관한 연구

학위논문(석사) - 한국과학기술원 : 전기 및 전자공학과, 2010.2, [ viii, 83 p. ]Recently, as the technology of fabrication for nano-sized structure is developed, NEMS(Nano-Electro-Mechanical System) are attracting attention due to their small size. Nanomechanical resonators or NEMS present interesting possibilities in a number of application as well as fundamental research. Due to high resonant frequency(~MHz), very small mass, low intrinsic dissipation which is limited at microscale dimensions, demonstrations and applications of unprecedented sensitivity available from nanomechanical devices such as sub-single-charge electrometry, single-electron-spin paramagnetic resonance, zeptogram scale mass sensors, and sub-femto-metre displacement sensing. In this thesis, MHz range nanomechanical resonator is demonstrated and developed based upon novel material titanium nitride which superior properties than other materials such as SiC, AlN, Si, GaAs. Proposed titanium nitride material has many advantages for nano-mechanical resonator in view of fabrication, design, performance, SNR. Using conventional CMOS-compatible fabrication, we made a stiff doubly clamped beam composed of only poly-crystalline titanium nitride without additional metal layer and temperature of fabrication is 300\degC which is very low thermal budget to fertile the reliable imbedded CMOS-circuit. At the same time, processing for making suspended structure is very simple and reliable. Due to constructing beam with single material, devices achieve a high quality factor without no interfacial friction and loss. In addition, titanium nitride have a high elastic modulus of 400~600GPa, which results high resonant frequency and sensitivity. Fundamental characterization of doubly clamped beam based upon titanium nitride were measured and compared with other research group. Maximum resonant frequency is obtained to about 135MHz with 2600 of quality factor which performance reach the $4 \times 10^{11}$ value. This performance is comparable or superior to other research group which sho...한국과학기술원 : 전기 및 전자공학과