• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.114-120
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• 1994

Esterolysis reactions of PNPDPP (p-nitrophenyldiphenylphosphate) by DCI ( dichloroisocyanuric acid sodium salt) in borate buffer pH8.0 micellar phase were studied. The rate of hydrolysis reaction was rapidly increased by adding cationic surfactants, CTAC (cetyltrimethylammonium chloride) or CTAB (cetyltrimethylammonium bromide), to the DCI solution. Especially in CTAB micellar system, the N-Cl bond of DCI was transformed to the N-Br bond during the reaction.

• Proceedings of the Korean Society for Information Management Conference
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• 2017.08a
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• pp.102-102
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• 2017

디지털 정보의 폭발적인 증가세와 함께 연구 데이타 또한 다양한 형태로 축적 되고 있다. 이에 다양한 정보들을 효율적으로 활용하는 것이 연구 혁신의 동력원으로 작용하고 어떠한 데이터를 어떻게 효율적으로 활용할 것인가가 정보 사회의 화두로 떠오르고 있다. 특히, 데이타 정보의 경우 전세계 약 900개 이상의 레파지토리들이 다양한 구조와 플랫폼을 토대로 축적 되고 있어 이에 대한 엄선 된 데이터 레파지토리 정보를 WoS의 단일 플랫폼에서 손쉽게 취득 할 수 있는 DCI(Data Citation Index)에 대한 관심이 증가되고 있는 추세이다. 현재 DCI에는 330여 종의 레포지토리에 수록 된 650만개 이상의 레코드를 수록 중이며 매년 50만 건 이상의 레코드가 추가 되고 있다. DCI는 레포지토리의 메타데이터를 분석하고 WoS에서 보유하고 있는 정보와 취합하여 데이터를 재구성하고 구조화하여 위계 질서를 부여하고 각 레코드가 소스 레포지토리로 연결되도록 링크를 제공하여 데이터 열람 및 다운로드가 가능하도록 하며 WoS내에 관련 논문(SCIE급)이 있는 경우 논문 과 데이터 상호 간의 링크도 제공한다. 보다 체계적인 데이터 관리를 위한 정보의 구조화와 보다 전문적인 정보 검색을 위한 Taxonomic Data와 시소러스(Thesaurus) 정보를 통한 DCI의 활용을 통해 새로운 정보의 세계를 경험해 보자.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.459-459
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• 2021

오래 전부터 농업용수 취수 등의 목적을 위해 설치된 하천 내 횡단구조물이 약 34,000개에 달하고, 홍수피해 방지를 위해 하천변을 따라 많은 제방이 설치되어 있다. 특히 보, 낙차공, 교각 보호공 등의 횡단구조물은 흐름의 단차를 발생시킴으로써 어류의 이동 등 하천의 종적 연속성을 훼손 또는 단절하고 있어 하천 수생태계 연속성 확보 측면에서 매우 중요한 요인으로 볼 수 있다. 하천 종적 연속성과 관련된 연구는 북미, 호주, 유럽, 일본 등에서 수생 종 특히, 어류를 중심으로 장벽의 영향을 분석하는 데 중점을 두고 진행되어 왔다. 하천 네트워크 규모에서 다수의 장벽 설치에 대한 누적 효과를 분석한 사례는 거의 없으며, 서식지 및 수생태계 연결과 관련하여, 하천 시스템의 네트워크 규모에서 속성을 설명하고 정량화하는 도구 역시 찾아보기 어렵다. 본 연구에서는 하천 네트워크 내의 종적 방향의 연결성을 정량화하기 위한 방법으로 Cote 등(2009)이 제시한 DCI(Dendritic Connectivity Index) 지표를 이용하였다. 수계 연속성 지표(DCI)는 하천 수계 내의 종적 연속성 평가를 목적으로 횡단구조물의 개소수와 위치, 어류의 이동률을 누적하여 정량화한 방법으로써, 구조물 단위 평가가 아닌 하천 단위 평가 방법이다. 곡성천과 삼척오십천을 대상으로 국가어도정보시스템 및 항공사진을 통해 구축한 구조물의 개소수와 위치정보를 이용하여 시계열 DCI를 산정하였다. 그리고 2차 조사에 걸쳐 횡단구조물 현황 및 수리 특성, 어류현황 및 이동특성 조사 및 분석결과를 DCI에 반영하여 DCIm을 산정하였다. 곡성천의 경우 현재(2018년) DCI 결과는 5.63%이며, 어류 이동률 적용 결과 DCIm은 6.29%로 산정되었고, 약 11.7% 증가하는 것으로 나타났다. 삼척오십천의 현재(2018년) DCI 결과는 9.78%이며, 어류 이동률 적용결과 DCIm은 10.34%로 산정되었고, 약 5.7% 증가하는 것으로 나타났다. 향후 하천 내 수생태계의 연속성을 확보하기 위해서는 우선적으로 하천 수생태계 훼손, 단절, 연속을 효과적으로 비교·평가할 수 있으며, 이를 통해 개선사업의 우순순위 등 의사결정을 위한 방법론의 개발이 필요하다.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.236-244
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• 2022

Objective : To evaluate the interactions among differentially expressed autophagy and mitophagy markers in subarachnoid hemorrhage (SAH) patients with delayed cerebral ischemia (DCI). Methods : The expression data of autophagy and mitophagy-related makers in the cerebrospinal fluid (CSF) cells was analyzed by real-time reverse transcription-polymerase chain reaction and Western blotting. The markers included death-associated protein kinase (DAPK)-1, BCL2 interacting protein 3 like (BNIP3L), Bcl-1 antagonist X, phosphatase and tensin homolog-induced kinase (PINK), Unc-51 like autophagy activating kinase 1, nuclear dot protein 52, and p62. In silico functional analyses including gene ontology enrichment and the protein-protein interaction network were performed. Results : A total of 56 SAH patients were included and 22 (38.6%) of them experienced DCI. The DCI patients had significantly increased mRNA levels of DAPK1, BNIP3L, and PINK1, and increased expression of BECN1 compared to the non-DCI patients. The most enriched biological process was the positive regulation of autophagy, followed by the response to mitochondrial depolarization. The molecular functions ubiquitin-like protein ligase binding and ubiquitin-protein ligase binding were enriched. In the cluster of cellular components, Lewy bodies and the phagophore assembly site were enriched. BECN1 was the most connected gene among the differentially expressed markers related to autophagy and mitophagy in the development of DCI. Conclusion : Our study may provide novel insight into mitochondrial dysfunction in DCI pathogenesis.

• Journal of the Korean Society for information Management
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• v.34 no.3
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• pp.109-124
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• 2017

Through a wide variety of disciplines, practices on data access and re-use have been increased recently. In fact, there has been an emerging phenomenon that researchers tend to use the data sets produced by other researchers and give scholarly credit as citation. With respect to this practice, in 2012, Thomson Reuters launched Data Citation Index (DCI). With the DCI, citation to research data published by researchers are collected and analyzed in a similar way for citation to journal articles. The purpose of this study is to identify the characteristics and intellectual structure of sociology field based on research data, which is one of actively data-citing fields. To accomplish this purpose, two data sets were collected and analyzed. First, from DCI, a total of 8,365 data were collected in the field of sociology. Second, a total of 12,132 data were collected from Web of Science with a topic search with 'Sociology'. As a result of the co-word analysis of author provided-keywords for both data sets, the intellectual structure of research data-based sociology was composed of two areas and 15 clusters and that of article-based sociology was composed with three areas and 17 clusters. More importantly, medical science area was found to be actively studied in research data-based sociology and public health and psychology are identified to be central areas from data citation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.9
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• pp.1736-1745
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• 2002

The objective of this study is to predict the roll wear in hot rod rolling process. In this study hot rod rolling process for round and oval passes has been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental form and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the thermal softening of DCI (Ductile Cast Iron) roll according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering parameter curve. 3D wear program developed in this study might be used for adjusting the gap of rolls to set up a suitable rolling schedule for keeping dimensional tolerance of the product.

• Tribology and Lubricants
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• v.33 no.3
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• pp.98-105
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• 2017

A pin-on-disk test is performed to measure the wear volume of a ductile cast iron (DCI) roll when it wears down using a high carbon steel and two alloy steels at different sliding velocities between the roll and the material (steel). Normal pressure is set as constant and test temperatures are 400, 500 and $600^{\circ}C$. In addition, thermal softening behavior of the DCI roll is examined using a high-temperature micro-hardness tester and the surface hardness variation of the DCI roll is expressed in terms of temperature and heating time. Based on experimental data, a wear coefficient used in Archard's wear model for each material is obtained. The wear volume is clearly observed when the test temperature is $400^{\circ}C$ and sliding velocity varies. However, it is not measured at temperatures of $500^{\circ}C$ and $600^{\circ}C$ even with variations in sliding velocity. From the optical photographs of the pin and disk, the abrasive wear is observed at $400^{\circ}C$ clearly, but no at $500^{\circ}C$ and $600^{\circ}C$. At higher temperatures, the pin surface is not smooth and has many tiny caves distributed on it. It is found that wear volume is dependent on the carbon contents rather than alloy contents. Results also reveal that the variations of wear coefficients are almost linearly proportional to the carbon contents of the material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.243-253
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• 2018

This study aimed to investigate the effects of DCI on glucose control, quality of life(SF-36 Version 2.0, Korean) and SDSCA(Summary of Diabetes Self-Care Activities) in patients with type 2 diabetes mellitus. A randomized, double-blind, placebo-controlled study was performed on 46 patients with HbA1c 7.0% taking triple anti-diabetic drug regimen who visited the department of Endocrinology and Metabolism in Chungnam National University Hospital between March 2015 and May 2016. As a result, DCI treatment in the intervention group resulted in significantly reduced HbA1c levels $8.75{\pm}0.79%$(baseline), $8.36{\pm}1.03%$(after 12weeks), and $8.65{\pm}0.81%$(after 24weeks). However, patients in the control group did not show any significant change. Interestingly, both DCI treatment group and the control group significantly showed improvements in SDSCA. Participants in the intervention group showed a small yet significant improvement in their only fasting blood glucose test in SDSCA and revealed significant increase in the quantitative levels of quality of life, from $73.05{\pm}16.85$ to $82.74{\pm}10.68$. By using pathway analysis, improvement of SDSCA scores(${\beta}=-0.505$, t=-2.743) was the most influential factor to the fasting blood glucose. The quality of life of patients with type 2 diabetes mellitus was affected by changes of SDSCA scores(${\beta}=0.411$, t=2.024) and fasting c-peptide(${\beta}=-0.445$, t=-2.668) in DCI treatment group. In conclusion, treatment of DCI effectively improved glucose control in patients with type 2 DM(HbA1c level>7.0%) after 12 weeks of treatment, although it had no impact on glucose control after 24 weeks of treatment. Improved glucose control may encourage diabetic patients to conduct self-care activities and improve the quality of life. Based on the present study, we suggest that diabetes self-management, as well as consideration of comprehensive laboratory findings, may be important factor in regulating the quality of life in type 2 DM patients.

• Journal of Korea Foundry Society
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• v.17 no.6
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• pp.577-584
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• 1997

Evaluation of rolling contact fatigue damage as well as material development for roll of rolling mill is being studied until quite recently. In this paper, a focus has been imposed on evaluating the rolling contact fatigue damage. In order for this, the accumulating process of rolling contact damage using the ferritic, pearlitic and bainitic DCI has been analyzed by X-ray diffraction technique. The main finds are; 1) The graphite in DCI is considered to be a cause of interfering in the redistribution of stress. Eventually, it results in the branching of crack. 2) The evaluation of rolling contact fatigue damage can be estimated in terms of the change of residual stress and/or a half-value breadth on surface during rolling contact.

• Journal of the Korean Society for Heat Treatment
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• v.9 no.4
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• pp.261-270
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• 1996

Boriding is one of the chemical methods to achieve the case hardening of steel as well as nitriding or carburizing. The surface layer of the borided steel shows higher hardness and exhibits better resistance to corrosion or fatigue than the nitrided or carburized steel. The great majority of previous studies were confined to mild steel or some alloy steel. To enlarge the application, ductile cast iron (DCI) as a material for boriding has been tried in this study. Thus, sliding wear test has conducted using a pin-on-disc machine to compare between borided DCI and mild steel in fluidized bed furnace. The results show that the wear resistance of borided DCI is improved. Especially it is more efficient in the case of occurence of the mechanical wear.