적층제조 공정으로 제조한 Co-Cr-Mo 합금의 미세조직과 기계적 물성에 대한 연구

정지호 한양대학교 대학원 2023 국내석사

This work investigated the effect of line energy on microstructures and mechanical properties of Co-Cr-Mo alloy single-track fabricated by the directed energy deposition (DED) method was investigated. As the line energy increased, the Co-Cr-Mo alloy single-track became wide and thick, and the thickness of the fusion zone at the interface increased because of the enthusiastic reaction with the substrate material. The Co-Cr-Mo alloy single-track with low line energy has a columnar grain microstructure with a strong (0 0 1)γ texture parallel to the build direction. In contrast, the single-tracks with high line energy have mixed microstructure, including fine columnar grains and coarse equiaxed grains, with random texture. In addition, the SDAS of the single-track depends on the line energy due to the rapid cooling rate. The diffusion of alloying elements from the substrate material throughout the fusion zone occurred and influenced the chemical composition and mechanical properties of the Co-Cr-Mo alloy single-track. The single-track with high line energy has poor hardness and low elastic modulus because the line energy determines the diffusion of alloying elements. The rapid cooling rate induces residual stress, which promotes the strain-induced ε-Co phase in the Co-Cr-Mo alloy single-track. The effect of the ε-Co phase on the mechanical properties of the single-track is insignificant.

직장인들의 생활체육 참여에 따른 스트레스 해소

정지호 신라대학교 교육대학원 2001 국내석사

듀얼 스캔 소나의 최적의 주파수 영역을 이용한 수중점검 기법에 관한 연구

정지호 세종대학교 대학원 2015 국내석사

현재 국내에는 교량의 붕괴에 따른 많은 인명피해 및 교량의 교체와 보수에 의해 발생하는 사회적, 경제적 손실이 증가하고 있다. 특히, 우리나라는 주기적이고 지속적으로 발생하는 집중호우와 태풍으로 인하여 교량의 피해가 급증하고 있는 실정이다. 대부분의 교량의 안전점검과 유지관리는 주로 상부구조의 내구성 및 내하성에 집중되어 왔으며, 실제 교량피해 원인의 대부분을 차지하고 있는 홍수 시 세굴에 의한 교각의 손상 예측 및 저감에 대한 연구와 투자는 미흡한 실정이다. 또한 국내에는 토목기술자이면서 잠수부 기능 자격을 갖춘 인력이 부족하여 교량의 수중점검 시 정확한 안전진단이 거의 불가능한 실정이다. 또한 잠수부에 의한 수중점검은 수중이라는 특수한 환경 때문에 수중점검에 많은 제약을 받게 된다. 최근 초음파 장비의 발전으로 많은 고분해능 소나장비가 개발되었다. 하지만 이러한 소나 장비를 이용한 체계적이고 효율적인 수중점검 시스템이 존재하지 않는다. 따라서 본 연구에서는 잠수부가 직접 교각의 수중점검을 실시하지 않아도 정확하고 안전하게 수중조사를 실시할 수 있도록 듀얼 소나 장비와 일체화형 시스템을 개발하였고, 실내실험을 통하여 검증된 듀얼 소나 시스템을 이용하여 실제 교량 및 수중구조물에 적용하였다.

고추,참깨,땅콩 連作地土壤의 微生物相과 Phytotoxins에 관한 硏究

정지호 圓光大學校 1991 국내박사

泰州學派와 그 思想의 社會史的 性格 : 王心齊를 中心으로

鄭址鎬 慶熙大學校 大學院 1993 국내석사

傳統中國における合과と經營の史的硏究

정지호 東京大學 2000 해외박사

원형 패턴 벡터를 이용한 인쇄체 한글 인식

정지호 아주대학교 대학원 2000 국내석사

워크플로우 기반의 통합브로커 설계 및 효율적인 비즈니스 트랜잭션 관리

鄭至鎬 忠南大學校 大學院 2004 국내박사

The market is getting more competitive and the demand from customers are diverse. Companies need to respond in time to the market to be changed quickly by the requirements of customers. It requires automating business processes beyond automating functions in companies. It is important to integrate all applications in companies before automating business processes. Nowadays asynchronous, loosely-coupled integration methods, which are represented by EAI (Enterprise Application Integration) and Web Services, are being applied to integrate un-interoperable applications developed by different technologies and standards. It is very hard to manage business transactions that occur in loosely-coupled integration because they can be processed through several organizations on the Internet. Standard protocols like BTP (Business Transaction Protocol) and WS-T (Web-Service Transaction) have been proposed to manage business transactions. However, they do not consider the efficiency because of appliance of unconditional rollback in their protocols in case of the “abort” due to the 2-phase commit protocol (2 PCP). This thesis designs an integration broker to integrate enterprise applications, which is functioned as a manager of business processes and a MOM. Also, this thesis proposes an efficient protocol to manage business transactions for loosely-coupled integration like the proposed integration broker. The propose protocol prevents the unconditional rollback and improves the success rate for execution of transactions by “classifying” the sub-transaction according to its weight and “retrying” when applicable. It does the classification and decision through the “classify phase” between Phase 1 and 2 of 2PCP. The proposed protocol is called "Classified Transaction Model(CTM)”. The efficiency of CTM is compared with BTP and is certified through an example of processing a business transaction.

보릿짚施用이 논土壤의 生化學性에 미치는 影響

정지호 全南大學校 大學院 1984 국내석사

보릿짚施用이 水稻栽培 논土壤에 미치는 影響을 규명하기 위하여 透水를 실시하여 土壤中 室素固定에 관여하는 微生物, 酵素活性, 糖 및 Acetylene 還元力을 조사分析한 結果를 要約하면 다음과 같다. 室素固定 微生物中 Azotobacter는 經時的으로 增加하였고 栽培區에서 보릿짚施用에 의해 17.61xl0⁴個로 增加하였으며 Clostridia는 栽培區에서 보릿짚施用에 의해 분얼기에 34 .56×10⁴個로 增加하였다가 그 後에는 0.3×10⁴個로 減少하였다. Blue-green algae는 출수기에 18.0x10³個로 增加하였다가 그 後에는 0.46x10⁴個로 減少하였는데 보릿짚施用에 의해 增加하는 傾向이었다. 酵素活性의 變化는 β-glucosidase가 출수기에 426.80μmole/g/hour로 크게 增加하였다가 그 後에는 7l.64μmole/g/hour로 減少하였으며 Phosphatase는 無栽培區에서 經時的으로 減少하였으나 栽培區에서는 經時的으로 增加하였다. Protease는 출수기에 73 .1μmole/g/hour로 增加하였으며 보릿짚施用에 의해 분얼기 無栽培區에서 94.71μmole/g/hour, 출수기 栽培區에서 73.1μmole/g/hour로 增加하였다. 土壤中 糖의 變化는 經時的으로 減少하였으며 보릿짚施用에 의해 분얼기栽培區의 Hexose가 58.73㎍/g로 크게 增加되었다. Acetylene還元力은 출수기에 0.012nmole/g/hour로 減少하였다가 성숙기에 0.44nmole/g/hour로 增加하였으며 보릿짚施用에 의한 뚜렷한 差異는 없었다. 有機物의 形態는 Ligno-Protein이 栽培區와 無栽培區에서 보릿짚旅用에 의해 各各 3840.7mg/l00g dry soil 3898.6mg/l00g dry soil로 가장 높았다. To investigate the effects of barley straw on microflora, enzyme activity, sugar and acetylene reducing activity in relation to nitrogen fixation in submerged soil. The results analysed were summarized as follows; Of the nitrogen fixing microorganisms, the number of Azotobactor tended to increase with the application of barley straw as the rice grew. The number of Clostridia observed to increase at the tillering stage of plant and to decrease thereafter, and that of Blue-green algae observed tend to increase at the heading stage and to decrease thereafter. On the other hand, the number of Blue green algae tended to increase by the application of barley straw. In submerged soil with barley straw applied, enzyme activity of β-glucosidase was to increase significantly but that of phosphatase was could not entirely control. Of the change of enzyme activity, β-glucosidase observed to increase at the heading stage and to decrease thereafter, and phosphatase tended to decrease in the submerged soil when rice plants were not cultured and to increase in the submerged soil when rice plants were cultured. Protease was tended to increase in the heading stage and increased in the tillering stage and heading stage with barley straw applied. The change of sugar was tended to decrease and hexose was increased in the tillering stage with barley straw applied. Acetylene reducing activity observed to decrease in the heading stage and to increase in the harvesting stage. There was no difference of acetylene reducing activity between the barley straw applied and barley straw not applied.

Structure determination of transmembrane protein associated with human diseases by NMR spectroscopy

정지호 韓國外國語大學校 大學院 2019 국내박사

Transmembrane proteins have a wide variety of physical-chemical properties and structures that connect the outside and the inside of the cell across the biological membrane. Based on these properties, they play an important role as enzymes, channels, receptors or transporters to enable many cells to function. It is important to understand their structure in order to understand their functions and biological mechanisms and make related drugs, but only a small number of structures, about 2% of total proteome size, are known. Syndecans are the main cell surface HSPGs connected to the plasma membrane by the transmembrane domain, i.e., it is one of transmembrane proteoglycans. The ecto-, TM, and cyto-domains of all syndecans function by forming dimers, which are homodimerized or heterodimerized by the conserved GxxxG dimerization motif present in the TM. They have a TM domain of similar amino acid sequence, but differ in levels of self-association, which means that syndecan members direct different functional interactions. Here, I investigated the structure of the Syd4 TM domain and the cyto-domain for understand to their dimerization and ligand binding behavior. In order to better understand the dimerization structure of the TM domain of Syd4, wild type (wt-) and mutant type (m-) TM were expressed, separated and purified, and structural studies were carried out using NMR spectroscopy.