• Structural Engineering and Mechanics
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• 제27권5호
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• pp.625-638
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• 2007

The damage detection process may appear difficult to be implemented for truss structures because not all degrees of freedom in the numerical model can be experimentally measured. In this context, the damage locating vector (DLV) method, introduced by Bernal (2002), is a useful approach because it is effective when operating with an arbitrary number of sensors, a truncated modal basis and multiple damage scenarios, while keeping the calculation in a low level. In addition, the present paper also evaluates the noise influence on the accuracy of the DLV method. In order to verify the DLV behavior under different damages intensities and, mainly, in presence of measurement noise, a parametric study had been carried out. Different excitations as well as damage scenarios are numerically tested in a continuous Warren truss structure subjected to five noise levels with a set of limited measurement sensors. Besides this, it is proposed another way to determine the damage locating vectors in the DLV procedure. The idea is to contribute with an alternative option to solve the problem with a more widespread algebraic method. The original formulation via singular value decomposition (SVD) is replaced by a common solution of an eigenvector-eigenvalue problem. The final results show that the DLV method, enhanced with the alternative solution proposed in this paper, was able to correctly locate the damaged bars, using an output-only system identification procedure, even considering small intensities of damage and moderate noise levels.

• 정보처리학회논문지A
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• 제18A권4호
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• pp.151-158
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• 2011

다양한 산업의 기업들은 비용 절감과 판매 촉진을 목적으로 물류 관리 기법들을 도입하여 왔으나, 물류 환경이 급변함에 따라서 적절한 물품을 빠르고(Speedy), 안전하고(Safely), 확실하고(Surely), 저렴하게(low) 고객에게 제공하는 물류 관리의 기본적인 3S 1L 원칙의 균형이 물류 실행 중에 지켜지지 않아서 기업에 위해를 입히는 현상이 확인되었다. 이러한 현상을 관리하기 위해서는 기업은 물류 환경에 유연하게 대응하는 위험 대처 능력이 절대적으로 필요하다. 특히 3자 물류 형태에서 공급망 위험관리의 주요 의사결정자인 화주의 지속적인 물류 정보 수집과 물류업체와의 정보 교류가 요구된다. 하지만 기존의 위험 관리 시스템은 다양한 화주의 요구, 긴급한 위험 상황에서 신속한 위험 인지와 대응을 하기에 미흡하다. 따라서 본 논문에서는 이러한 문제점을 해결하기 위하여 기존 위험관리 연구를 고찰하여 위험 요인을 정리하고 능동적 공급망 위험관리 시스템 프레임워크를 제시하였다. 또한 기존 시스템과의 대응 활동을 비교한 안정성 검사를 통해 효율성을 검증하였다.

• 한국컴퓨터정보학회지
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• 제14권2호
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• pp.159-164
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• 2006

제조실행시스템(MES: Manufacturing Execution System)은 현장(shop floor)에서 작업을 수행하기 위한 제반 활동 (스케줄링, 작업 프로세스, 품질관리, 등)을 지원하기 위한 관리 시스템이다. 특히, MES는 생산계획과 실행의 차이를 줄이기 위한 시스템으로 현장상태의 실시간 정보제공을 통하여 관리자와 작업자의 의사결정을 지원하는 기능을 수행한다. 실시간 정보처리를 위한 MES는 최근 많은 관심을 가지고 있는 RFID의 Data를 모델링하고, 제조부터 판매까지 각 프로세스 내의 제품을 모니터링 하는 기능이 필요하다. 그러나, RFID가 부착된 제품이 프로세스 과정에 있어서, tag, reader의 오작동, 고의적 파손, 분실, 주변 영향으로 인해, 리더기가 tag를 읽지 못하는 경우, 제품의 위치를 모니터링 할 수 없다. 이러한 경우, 불확실한 정보를 가지고 제품의 경로를 추적하여야만 한다. 본 논문은 신속하게 제품을 찾기 위해, RFID와 Bayesian Network을 이용한 MES를 제안하고 성능을 평가하였다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.64-64
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• 2018

The genus Cenchrus (Poaceae), containing ca. 97 species, is distributed throughout Australia, Africa and Indian sub-continent and which was introduced to the United States and Mexico for use in improved pasture. In Korea, especially Daecheong Island, it is one of the most hazardous invasive plant, which causes serious environmental threats, biodiversity damages and physically negative impact on humans and animals. It can cause serious damage to farms, fields and white sand beaches. However, the chloroplast (cp) genome sequences and information of Cenchrus longispinus have been not addressed, so we provide the complete cp genome of Cenchrus longispinus using next-generation sequencing technology. The size of cp genomes of this Daecheong Island species (Cenchrus longispinus) is 137,144 bp, and it shows a typical quadripartite structure. Consisting of the large single copy (LSC; 80,223 bp), small single copy (SSC; 12,449 bp), separated by a pair of inverted repeats (IRs; 22,236 bp). This cp genome contains 75 unique genes, 4 rRNA coding genes, 33 tRNA coding genes and 21 duplicated in the IR regions, with the gene content and organization are similar to other Poaceae cp genomes. Our comparative analysis identified four cpDNA regions (rpl16, rbcL, ndhH and ndhF) from three Cenchrus species, two Setaria species and one Pennisetum species which may be useful for molecular identification.

• Structural Engineering and Mechanics
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• 제54권2호
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• pp.257-289
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• 2015

Shear connectors are generally used to link the slab and girders together in slab-on-girder bridge structures. Damage of shear connectors in such structures will result in shear slippage between the slab and girders, which significantly reduces the load-carrying capacity of the bridge. Because shear connectors are buried inside the structure, routine visual inspection is not able to detect conditions of shear connectors. A few methods have been proposed in the literature to detect the condition of shear connectors based on vibration measurements. This paper proposes a different dynamic condition assessment approach to identify the damage of shear connectors in slab-on-girder bridge structures based on power spectral density transmissibility (PSDT). PSDT formulates the relationship between the auto-spectral densities of two responses in the frequency domain. It can be used to identify shear connector conditions with or without reference data of the undamaged structure (or the baseline). Measured impact force and acceleration responses from hammer tests are analyzed to obtain the frequency response functions at sensor locations by experimental modal analysis. PSDT from the slab response to the girder response is derived with the obtained frequency response functions. PSDT vectors in the undamaged and damaged states can be compared to identify the damage of shear connectors. When the baseline is not available, as in most practical cases, PSDT vectors from the measured response at a reference sensor to those of the slab and girder in the damaged state can be used to detect the damage of shear connectors. Numerical and experimental studies on a concrete slab supported by two steel girders are conducted to investigate the accuracy and efficiency of the proposed approach. Identification results demonstrate that damages of shear connectors are identified accurately and efficiently with and without the baseline. The proposed method is also used to evaluate the conditions of shear connectors in a real composite bridge with in-field testing data.

• Safety and Health at Work
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• 제10권4호
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• pp.393-399
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• 2019

Objective: This study investigates the impact of multimorbidity on work through a literature review of longitudinal studies. Methods: A systematic review was carried out in the databases Lilacs, SciELO, PAHO, PubMed/Medline, Scopus, Web of Science, and Cochrane. There were no restrictions regarding the year of publication or language to maximize the identification of relevant literature. The quality of studies was assessed by the protocol STrengthening the Reporting of OBservational studies in Epidemiology (STROBE). Results: An initial database search identified 7522 registries, and at the end of the analysis, 7 manuscripts were included in the review. Several studies have demonstrated direct and indirect impacts of multimorbidity on the health of workers. For this, the number of missed days due to health-related issues was evaluated, as well as the reduction in work productivity of the unhealthy worker, vulnerability of the worker with multimorbidity regarding higher indices of dismissal and recruitment difficulties, and incidence of early retirement and/or receipt of benefits due to disabilities. Conclusions: Multimorbidity has a negative impact on work, with damages to quality of life and work productivity, worsening the absenteeism/presenteeism indices, enhancing the chances of temporary or permanent leaves, and lowering employability and admission of individuals with multimorbidity.

• 농촌계획
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• 제19권3호
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• pp.51-59
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• 2013

The objective of this study was to make a map of farmland vulnerability to flood inundation based on morphologic characteristics from the flood-damaged areas. Vulnerability mapping based on the records of flood damages has been conducted in four successive steps; data preparation and preprocessing, identification of morphologic criteria, calculation of inundation vulnerability index using a fuzzy membership function, and evaluation of inundation vulnerability. At the first step, three primary digital data at 30-m resolution were produced as follows: digital elevation model, hill slopes map, and distance from water body map. Secondly zonal statistics were conducted from such three raster data to identify geomorphic features in common. Thirdly inundation vulnerability index was defined as the value of 0 to 1 by applying a fuzzy linear membership function to the accumulation of raster data reclassified as 1 for cells satisfying each geomorphic condition. Lastly inundation vulnerability was suggested to be divided into five stages by 0.25 interval i.e. extremely vulnerable, highly vulnerable, normally vulnerable, less vulnerable, and resilient. For a case study of the Jinju, farmlands of $138.6km^2$, about 18% of the whole area of Jinju, were classified as vulnerable to inundation, and about $6.6km^2$ of farmlands with elevation of below 19 m at sea water level, slope of below 3.5 degrees, and within 115 m distance from water body were exposed to extremely vulnerable to inundation. Comparatively Geumsan-myeon and Sabong-myeon were revealed as the most vulnerable to farmland inundation in the Jinju.

• Molecular & Cellular Toxicology
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• 제1권4호
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• pp.230-236
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• 2005

Formaldehyde is a common environmental contaminant found in tobacco smoke, paint, garments, diesel and exhaust, and medical and industrial products. Formaldehyde has been considered to be potentially carcinogenic, making it a subject of major environmental concern. However, only a little information on the mechanism of immunological sensitization and asthma by this compound has been known. So, we performed with Jurkat cell line, a human T lymphocyte, to assess the induction of DNA damage and to identify the DEGs related to immune response or toxicity by formaldehyde. In this study, we investigated the induction of DNA single strand breaks by formaldehyde using single cell gel electrophoresis assay (comet assay). And we compared gene expression between control and formaldehyde treatment to identify genes that are specifically or predominantly expressed by employing annealing control primer (ACP)-based $GeneFishing^{TM}$ method. The cytotoxicity ($IC_{30}$) of formaldehyde was determined above the 0.65 mM in Jurkat cell in 48 h treatment. Based on the $IC_{30}$ value from cytotoxicity test, we performed the comet assay in this concentration. From these results, 0.65 mM of formaldehyde was not revealed significant DNA damages in the absence of S-9 metabolic activation system. And the one differentially expressed gene (DEG) of formaldehyde was identified to zinc finger protein 292 using $GeneFishing^{TM}$ method. Through further investigation, we will identify more meaningful and useful DEGs on formaldehyde, and then can get the information on the associated mechanism and pathway with immune response or other toxicity by formaldehyde exposure.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2001년도 학술대회지
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• pp.46-53
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• 2001

정부의 지속적인 사회간접시설의 건설로 많은 대형공공공사가 발주되고 있으며, 이에 따라 많은 건설 클레임이 발생되고 있으며, 그 .중에서도 현장여건상이 클레임은 발생가능성이 높은 부분이다. 특히 현장여건상이 클레임은 여타 클레임과 달리 공사 초기에 발생하여 여타의 클레임보다 큰 손실을 초래할 수 있으므로 이에 대한 예방방안의 필요성이 증대되고 있다. 본 연구는 국내의 대형공공공사 중 일괄공사계약으로 발주된 공사에서 발생한 현장여건상이 클레임의 원인을 분석하고, 향후 이러한 클레임을 예방할 수 있는 예방방안을 제시하였다. 본 연구에서 제시하고 있는 예방방안으로는 첫째 수급자의 입찰관행 개선, 둘째 수급자의 현장조사 책임한계 정립, 셋째 발주자의 면책조항 재검토 그리고 마지막으로 계약금액 조정의 유연성을 확보하기 위한 방안 등을 제시하고 있다. 또한 상기의 예방방안에 대한 단·장기적 대안도 제시했다. 이러한 예방방안들은 발주자와 수급자 사이에서 현장여건상이 클레임의 해결에 사용될 수 있을 것으로 판단된다.

• 한국컴퓨터정보학회논문지
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• 제11권5호
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• pp.211-221
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• 2006

MES는 산업전반에서 시스템의 정보를 빠르게 공유하고 의사결정에 도움을 주며, 생산현장에서의 신속한 정보 획득과 처리를 하여, 종합적 정보 관리를 효율적으로 할 수 있다. 실시간 정보처리를 위한 MES는 최근 많은 관심을 가지고 있는 RFID의 Data를 모델링하고, 제조부터 판매까지 각 프로세스 내의 제품을 모니터링 하는 기능이 필요하다. 그러나, RFID가 부착된 제품이 프로세스 과정에 있어서, tag, reader의 오작동, 고의적 파손, 분실, 주변 영향으로 인해, 리더기가 tag를 읽지 못하는 경우, 제품의 위치를 모니터링 할 수 없다. 이러한 경우, 불확실한 정보를 가지고 제품의 경로를 추적하여야만 한다. 본 논문은 신속하게 제품을 찾기 위해, RFID와 Bayesian Network을 이용한 MES를 제안하고 성능을 평가하였다.