• Earthquakes and Structures
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• 제24권4호
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• pp.303-316
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• 2023

Rapid post-earthquake damage estimation of subway stations is particularly necessary to improve short-term crisis management and safety measures of urban subway systems after a destructive earthquake. The conventional Performance-Based Earthquake Engineering (PBEE) framework with constant earthquake occurrence rate is invalid to estimate the aftershock risk because of the time-varying rate of aftershocks and the uncertainty of mainshock-damaged state before the occurrence of aftershocks. This study presents a time-varying probabilistic seismic risk assessment framework for underground structures considering mainshock and aftershock hazards. A discrete non-omogeneous Markov process is adopted to quantify the time-varying nature of aftershock hazard and the uncertainties of structural damage states following mainshock. The time-varying seismic risk of a typical rectangular frame subway station is assessed under mainshock-only (MS) hazard and mainshock-aftershock (MSAS) hazard. The results show that the probabilities of exceeding same limit states over the service life under MSAS hazard are larger than the values under MS hazard. For the same probability of exceedance, the higher response demands are found when aftershocks are considered. As the severity of damage state for the station structure increases, the difference of the probability of exceedance increases when aftershocks are considered. PSDR=1.0% is used as the collapse prevention performance criteria for the subway station is reasonable for both the MS hazard and MSAS hazard. However, if the effect of aftershock hazard is neglected, it can significantly underestimate the response demands and the uncertainties of potential damage states for the subway station over the service life.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2723-2733
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• 2023

Transuranic nuclides (such as ²³⁸Pu, ²⁵²Cf, ²⁴⁹Bk, etc.) have a wide range of application in industry, medicine, agriculture, and other fields. However, due to the complex conversion chain and remarkable fission losses in the process of transuranic nuclides production, the generation amounts are extremely low. High flux reactor with high neutron flux and flexible irradiation channels, is regarded as the promising candidate for producing transuranic nuclides. It is of great significance to increase the conversion ratio of transuranic nuclides, resulting in higher efficiency and better economy. In this paper, we perform an optimization design evaluation of producing transuranic nuclides in high flux reactor, which includes optimization design of irradiation target and influence study of reactor core loading. It is demonstrated that the production rate increases with appropriately determined target material and target structure. The target loading scheme in the irradiation channel also has a significant influence on the production of transuranic nuclides.

• 무역학회지
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• 제42권5호
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• pp.213-232
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• 2017

본 연구는 현재 시행되고 있는 BPO에 대해 제도적 차원에서 주요 쟁점으로 중심으로 신용장 제도와 비교하여 고찰하였다. BPO는 은행간의 약정이기 때문에 지급의무의 이행, 확인, 양도 등에 있어서 신용장제도와 차이를 보이며, 또한 유의해야 할 점이다. BPO은 기본적으로 기능 면에서 신용장과 유사하지만, 별개의 독립적인 제도로 운용되며 정보기술과 데이터를 기반으로 한다. 신용장을 포함한 전통적인 제도 보다는 더 효율적이며 비용 효과적이다. 따라서 전통적인 제도에 대한 전자적 대안으로 보여진다. 본 연구는 선행 연구를 중심으로 이미 발표된 BPO 관련 연구와 자료 등을 통하여 문헌 연구하였다.

• 영어영문학
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• 제58권4호
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• pp.723-752
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• 2012

Although his mythic poetry deals with the fall and resurrection of Albion as the origin of humankind, William Blake (1757-1827) simultaneously links it to the professionalization and unification of disciplinary knowledge itself. He particularly takes a great interest in the cross-referential relation of poetry to science. He argues for the communication of poetry and science on equal footing with each other without the former's prioritization over the latter, or vice versa. In his works Vala, or The Four Zoas (1797-1807) and Jerusalem: The Emanation of the Giant Albion (1804-1820), on which I focus in this essay, Blake's primary problematic is to display strong conflicts among different systems of knowledge. I approach this issue in light of the ideological clash of Newtonian thought, Romantic thought, and postmodern thought. In his poetry, Blake thematizes the very clashes of these different thought patterns. From the standpoint of Romantic thought, first of all, Blake problematizes Newtonian Enlightenment. He criticizes abstract universalization both in poetry and science, which Urizen, one of four Zoas, propagates. Protesting against Urizen's Newtonism, Los values "living form." Thus, Blake demonstrates, through this figure, that poetic imagination and scientific organicism are discursively communicative. Blake, however, also questions the network of Romantic science and Romantic poetry so as to suggest what current critics would call postmodern thought. Blakean postmodernism pursues the self-similarity of organic structure in science and poetry. Precisely, Blake sees polypus as a proliferation of organic body; he arranges four Zoas' self-repetitive stories in a non-linear way. Blake aspires for the conflicting coexistence of different thought patterns.

• Fisheries and Aquatic Sciences
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• 제26권9호
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• pp.569-581
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• 2023

The morphology and genetic identification of Rasbora lateristriata and Rasbora argyrotaenia between cultivated and wild populations has never been reported. This study compares morphology and cytochrome c oxidase (COI) genes between farmed and wild stock Rasbora spp. in Java and Sumatra island, Indonesia. We analyzed the truss network measurement (TNM) characters of 80 fish using discriminant function analysis statistical tests. DNA was extracted from muscle tissue of 24 fish specimens, which was then followed by polymerase chain reaction, sequencing, phylogenetic analysis, fixation index analysis, and statistical analysis of haplotype networks. Basic Local Alignment Search Tool analysis validated the following species: R. lateristriata and R. argyrotaenia from farming (Jogjakarta); Rasbora agryotaenia (Purworejo), R. lateristriata (Purworejo and Malang), Rasbora dusonensis (Palembang), and Rasbora einthovenii (Riau) from natural resources. Based on TNM characters, Rasbora spp. were divided into four groups, referring to four distinct characters in the middle of the body. The phylogenetic tree is divided into five clades. The genetic distance between R. argyrotaenia (Jogjakarta) and R. lateristriata (Malang) populations (0.66) was significantly different (p < 0.05). R. lateristriata (Purworejo) has the highest nucleotide diversity (0.43). R. argyrotaenia from Jogjakarta and Purworejo shared the same haplotype. The pattern of gene flow among them results from the two populations' close geographic proximity and environmental effects. R. argyrotaenia had low genetic diversity, therefore, increasing heterozygosity in cultivated populations is necessary to avoid inbreeding. Otherwise, R. lateristriata (Purworejo) had a greater gene variety that could be used to develop breeding. In conclusion, the middle body parts are a distinguishing morphometric character of Rasbora spp., and the COI gene is more heterozygous in the wild population than in farmed fish, therefore, enrichment of genetic variation is required for sustainable Rasbora fish farming.

• Journal of Life Science
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• 제11권2호
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• pp.111-115
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• 2001

This study was designed to clone the SNF2/SW12 helicase-related genes from the fission yeast Schizosaccha-romyces pombe and thereafter to elucidate the common functions of the proteins in this family. The $hrp^{2+}$gene was cloned by polymerase chain reaction amplification using degenerative primers from conserved SNF2 motifs within the ERCC6 gene, which encodes a protein involved in DNA excision repair. Like other SNF2/SW12 family proteins, the deduced amino acid sequence of Hrp2 contains DNA-dependent ATPase/7 helicase domains as well as the chromodomain and the DNA binding domain. This configuration is similar to that of mCHD1 (mouse chromo-ATPase/helicase-DNA-dinding protein 1), suggesting that Hrp2 is a S. pombe homolog of mCHD1, which is thought to function in altering the chromatin structure to control the gene expression. To characterize the function of Hrp2, 4 Uracil-Hrp2 fusion protein, it was purified near homogeneity by affinity chromatography on $Ni^{2+}$-NTA agarose, DEAE-Sepharose ion exchange arid Sephacryl S-200 gel filtration chromatographies. The purified fusion protein exhibited DNA-dependent ATPase activity, which was stimulated by both double-stranded and single-stranded DNA. To determine the steady-state level of $hrp^{2+}$ transcripts during growth, cells were cultured in medium and collected at every 2hr to prepare total RNAs. The northern blot analysis showed that the level of $hrp^{2+}$ transcripts reached its maximum before the cells entered the exponential growth phase and then decreased gradually, This result implies that Hrp2 may be required at early stages of cell growth.h.

• International Journal of Computer Science & Network Security
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• 제23권11호
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• pp.128-132
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• 2023

Investment authorities are broad financial institutions that carefully manage investments on behalf of the national government using a long-term value development approach. To provide a stronger structure or framework for In-vestment Authorities to govern the distribution of funds to public and private markets, we've started research to create a blockchain-based prototype for managing and tracking numerous finances of such authorities. We have taken the case study of Oman Investment Authority (OIA) of Sultanate of Oman. Oman's wealth is held in OIA. It is an organization that oversees and utilizes the additional capital generated by oil and gas profits in public and private markets. Unlike other Omani funds, this one focus primarily on assets outside the Sultanate. The operation of the OIA entails a huge number of transactions, necessitating a high level of transparency and administration among the parties involved. Currently, OIA relies on various manuals to achieve its goals, such as the Authorities and Responsibilities manual, the In-vestment Manual, and the Code of Business Conduct, among others. In this paper, we propose a Blockchain based framework to manage the operations of OIA. Blockchain is a part of the Fourth Industrial Revolution, and it is re-shaping every industry. The main components of every blockchain are assets and participants. The funds are the major assets in the proposed study, and the participants are the various fund shareholders/recipients. The block-chain's transactions are all safe, secure, and immutable, and it's part of a trustless network. The transactions are simple to follow and verify. By replacing intermediary firms with smart contracts, blockchain-based solutions eliminate any middlemen in the fund allocation process.

• Applied Biological Chemistry
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• 제3권
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• pp.25-48
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• 1962

tragacanth gum의 화학구조(化學構造)를 구명(究明)하기 위(爲)하여 미국(美國) 약전(藥典)의 tragacanth gum 분말(粉末)을 가지고 다음의 실험(實驗)을 통(通)하여 이의 성분(成分)의 하나인 polysaccharide C를 분리(分離)하여 이의 화학구조(化學構造)를 밝혔다. (1) tragacanth gum을 85% 주정(酒精)으로 처리(處理)해서 중성다당류(中性多糖類)로 polysaccharide C를 분리(分離)하였으며 구성당(構成糖)으로 L-rhamnose, D-xylose, L-arabinose 및 D-galactose를 paper chromatography와 Cellulose column chromatography로 분리(分離), 동정(同定)하였다. 이의 molar ratio는 2:1:17:9이며 비선광도(比旋光度)는 $[{\alpha}]^{30}_D-72.2이다. (2) 구성당(構成糖)의 결합위치(結合位置)를 구명(究明)하기 위(爲)해 Hawarth 법(法)과 Purdietldir(試藥)을 가지고 methyl화(化)시켜 methyl화(化) polysaccharide C를 얻었으며 비선광도(比旋光度) $[{\alpha}]^{22}_D-102를 보였다. 이것을 가수분해(加水分解)시켜 paper chromatography와 column chromatography를 통(通)해 methyl화단당(化單糖)으로 1,3,5-tri-O-methyl-L-arabofuranose, 3,4-di-O-methyl-L-rhamnose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-galactopyranose, 2,4-di-O-methyl-L-arabopyronose, 2,4-di-O-methyl-D-galactose, 2-O-methyl-L-arabinose 및 L-arabinose를 분리(分離), 동정(同定)하였다. (3) 산(酸)의 각종농도(各種濃度)에 따른 부분적(部分的) 가수분해(加水分解)를 시켜 polysaccharide C의 end group, 측지(側枝) 또는 주쇄(主鎖)를 이루는 구성당(構成糖)을 밝히기 위(爲)하여 0.05 N-HCl로 제1차(第一次) 가수분해(加水分解). 0.1N-HCl로 제2차(第二次) 가수분해(加水分解), 0.3N-HCl로 제3차(第三次) 가수분해(加水分解)를 하여 가수분해물(加水分解物)과 비가수분해물(非加水分解物)에서 각각(各各) 다음과 같은 구성단당(構成單糖)을 검출(檢出)하고 이들의 molar ratio를 측정(測定)하였다. 제1차(第一次) 가수분해물(加水分解物)(A)에서 L-arbinose, 비가수분해물(非加水分解物)(A')에서 L-rhamnose, D-xylose, L-arabinose 및 D-galactose; 제2차(第二次) 가수분해물(加水分解物)(B)에서 L-arabinose와 D-galactose, 비가수분해물(非加水分解物)(B')에서 L-rhamnose, D-xylose, L-arabinose, 및 D-galactose; 제3차(第三次) 가수분해물(加水分解物)(C)에서 L-rhamnose, D-xylose, L-arabinose 및 D-galactose, 비가수분해물(非加水分解物)(C')에서 D-xylose와 D-galactose를 검출(檢出)하였다. (4) 구성당(構成糖)의 형태(形態)와 구조(構造)를 밝히기 위(爲)해 polysaccharide C에 대한 periodate산화(酸化) 실험(實驗)을 하여 $C_5H_8O_4$당(當) periodate의 소비(消費)와 formic acid의 생성량(生成量)을 측정(測定)하였는데 periodate의 소비량(消費量)은 1.23 mole, formic acid의 생성량(生成量)은 0.78 mole이다.

• 한국막학회:학술대회논문집
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• 한국막학회 1999년도 The 7th Summer Workshop of the Membrane Society of Korea
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• pp.39-42
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• 1999

Perfluoropolymers represent the ultimate resistance to hostile chemical environments and high service temperature, attributed to the presence of fluorine in the polymer backbone, i.e. to the high bond energy of C-F and C-C bonds of fluorocarbons. Copolymers of Tetrafluoroethylene (TEE) and 2, 2, 4Trifluoro-5Trifluorometoxy- 1, 3Dioxole (TTD), commercially known as HYFLON AD, are amorphous perfluoropolymers with glass transition temperature (Tg)higher than room temperature, showing a thermal decomposition temperature exceeding 40$0^{\circ}C$. These polymer systems are highly soluble in fluorinated solvents, with low solution viscosities. This property allows the preparation of self-supported and composite membranes with desired membrane thickness. Symmetric and asymmetric perfluoropolymer membranes, made with HYFLON AD, have been prepared and evaluated. Porous and not porous symmetric membranes have been obtained by solvent evaporation with various processing conditions. Asymmetric membranes have been prepared by th wet phase inversion method. Measure of contact angle to distilled water have been carried out. Figure 1 compares experimental results with those of other commercial membranes. Contact angles of about 120$^{\circ}$for our amorphous perfluoropolymer membranes demonstrate that they posses a high hydrophobic character. Measure of contact angles to hexandecane have been also carried out to evaluate the organophobic character. Rsults are reported in Figure 2. The observed strong organophobicity leads to excellent fouling resistance and inertness. Porous membranes with pore size between 30 and 80 nanometers have shown no permeation to water at pressures as high as 10 bars. However high permeation to gases, such as O2, N2 and CO2, and no selectivities were observed. Considering the porous structure of the membrane, this behavior was expected. In consideration of the above properties, possible useful uses in th field of gas- liquid separations are envisaged for these membranes. A particularly promising application is in the field of membrane contactors, equipments in which membranes are used to improve mass transfer coefficients in respect to traditional extraction and absorption processes. Gas permeation properties have been evaluated for asymmetric membranes and composite symmetric ones. Experimental permselectivity values, obtained at different pressure differences, to various single gases are reported in Tab. 1, 2 and 3. Experimental data have been compared with literature data obtained with membranes made with different amorphous perfluoropolymer systems, such as copolymers of Perfluoro2, 2dimethyl dioxole (PDD) and Tetrafluorethylene, commercialized by the Du Pont Company with the trade name of Teflon AF. An interesting linear relationship between permeability and the glass transition temperature of the polymer constituting the membrane has been observed. Results are descussed in terms of polymer chain structure, which affects the presence of voids at molecular scale and their size distribution. Molecular Dyanmics studies are in progress in order to support the understanding of these results. A modified Theodoru- Suter method provided by the Amorphous Cell module of InsightII/Discover was used to determine the chain packing. A completely amorphous polymer box of about 3.5 nm was considered. Last but not least the use of amorphous perfluoropolymer membranes appears to be ideal when separation processes have to be performed in hostile environments, i.e. high temperatures and aggressive non-aqueous media, such as chemicals and solvents. In these cases Hyflon AD membranes can exploit the outstanding resistance of perfluoropolymers.

• 해양환경안전학회지
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• 제29권5호
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• pp.479-487
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• 2023

최근 지구 온난화의 영향으로 태풍의 파괴력이 증가함에 따라 부유식 해상풍력발전기의 막대한 유실과 붕괴에 대한 우려가 깊어지고 있다. 부유식 해상풍력발전기의 안전한 운영을 위해 새로운 형태의 탈착형 계류 시스템 개발이 요구되고 있다. 본 연구에서 고려한 새로운 반잠수식 계류 풀리는 기존의 탈착형 계류 장치에 비해 계류 라인으로 부유식 해상풍력 터빈을 보다 쉽게 탈부착할 수 있도록 고안되었다. 8MW급 부유식 해상풍력발전기에 적용 가능한 반잠수식 계류 풀리의 초기 설계에 대한 구조적 안전성을 검토하기 위해 3D 프린터를 이용하여 축소구조모형을 제작하고, 이 모형에 대한 구조시험을 수행하였다. 축소 모형의 구조시험을 위해 3D 프린팅에 사용된 ABS 소재의 인장 시편을 제작하고 인장시험을 수행하여 소재의 물성을 평가하였다. 인장시험에서 얻은 재료 특성과 축소모형 구조 시험과 동일한 하중 및 경계 조건을 적용하여 반잠수식 계류 풀리의 유한요소해석을 수행하였다. 유한요소해석을 통해 반잠수식 계류 풀리의 구조적 취약 부분을 검토하였다. 반잠수식 계류 풀리의 주요 하중조건을 고려하여 구조모형시험을 수행하였으며, 재료의 최대인장응력 이상이 발생하는 위치에 대해 유한요소해석과 시험 결과를 비교하였다. 유한요소해석과 모형시험의 결과로부터 작동조건에서는 Body와 Wheel의 연결부 구조가 취약한 것으로 파악되었고, 계류조건에서는 Body와 Chain stopper의 연결부 구조가 취약한 것으로 검토되었다. 축소모형 구조시험에서 나타난 SMP의 구조 취약부는 구조해석의 결과와 일치하는 것으로 나타났다. 연구 결과를 통해 반잠수식 계류 풀리의 초기 설계에 대한 구조적 안전성을 실험적으로 검증할 수 있었다. 또한, 본 연구 결과는 상세설계 단계에서 반잠수식 계류 풀리의 구조 강도를 향상시키는데 유용하게 활용될 수 있을 것으로 판단된다.