• Restorative Dentistry and Endodontics
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• 제43권3호
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• pp.24.1-24.12
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• 2018

Objectives: The aim of this in vitro study was to evaluate the biocompatibility of newly proposed root-end filling materials, Biodentine, Micro-Mega mineral trioxide aggregate (MM-MTA), polymethylmethacrylate (PMMA) bone cement, and Smart Dentin Replacement (SDR), in comparison with contemporary root-end filling materials, intermediate restorative material (IRM), Dyract compomer, ProRoot MTA (PMTA), and Vitrebond, using human periodontal ligament (hPDL) fibroblasts. Materials and Methods: Ten discs from each material were fabricated in sterile Teflon molds and 24-hour eluates were obtained from each root-end filling material in cell culture media after 1- or 3-day setting. hPDL fibroblasts were plated at a density of $5{\times}10^3/well$, and were incubated for 24 hours with 1:1, 1:2, 1:4, and 1:8 dilutions of eluates. Cell viability was evaluated by XTT assay. Data was statistically analysed. Apoptotic/necrotic activity of PDL cells exposed to material eluates was established by flow cytometry. Results: The Vitrebond and IRM were significantly more cytotoxic than the other root-end filling materials (p < 0.05). Those cells exposed to the Biodentine and Dyract compomer eluates showed the highest survival rates (p < 0.05), while the PMTA, MM-MTA, SDR, and PMMA groups exhibited similar cell viabilities. Three-day samples were more cytotoxic than 1-day samples (p < 0.05). Eluates from the cements at 1:1 dilution were significantly more cytotoxic (p < 0.05). Vitrebond induced cell necrosis as indicated by flow cytometry. Conclusions: This in vitro study demonstrated that Biodentine and Compomer were more biocompatible than the other root-end filling materials. Vitrebond eluate caused necrotic cell death.

• 대한지리학회지
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• 제46권2호
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• pp.181-196
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• 2011

본 연구의 목적은 최근의 경제 환경 변화 속에서 도시성장을 설명하는 새로운 모형으로 대두된 네트워크 도시를 심층적으로 이해하는 것이다. 이를 위하여 1990년대 중반 Batten(l995)의 시론적인 네트워크 도시 연구로부터 출발하여 현재에 이르기까지 관련 연구들을 정리하고 궁극적으로 네트워크 도시이론의 다양한 측면, 즉 형성과정, 공간구조, 관리 및 도시계획에의 응용, 성장에 대한 전망 등을 고찰해 봄으로써 네트워크 도시이론이 21세기의 도시현상을 설명하는데 적절한 이론인지에 대한 판단을 위해 필요한 포괄적인 지식을 제공하고자 한다. 관련연구들을 분석해본 결과 네트워크 도시는 경제의 세계화와 교통 및 정보통신기술의 발전과 함께 수반된 도시현상의 변화를 적절히 설명해 주는 이론일 뿐만 아니라 유럽을 중심으로 여러 도시정부들이 도시계획원리로 적극적으로 수용해 나가는 추세에 있는 유용한 개념으로 판단된다.

• 한국경제지리학회지
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• 제17권1호
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• pp.114-128
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• 2014

이 연구는 2008년부터 2011년까지의 고용보험통계를 이용하여 경력직 노동력 이동에 대해 16개 시도를 공간단위로 분석한 것이다. 우리나라 임금근로자 중 전체 상용직과 일부 임시 및 일용직 근로자가 고용보험 가입자이고, 이들 중 매년 약 40-50%의 경력직 근로자가 직장을 옮기고 있다. 이러한 고용보험 가입 경력직 노동력의 이동에 대해 첫째 전체 이동 근로자 대상으로 군집분석을 진행하여 그 권역을 탐색하고, 둘째 타 시도로 이동하는 근로자를 추출하고 유출비와 유입비를 이용해 지역 간 이동의 연계와 상호작용을 측정하였다. 분석결과, 이동권역은 지난 정부가 설정했던 5+2 광역경제권과 유사한 군집을 이루었지만, 지역 간 이동에 있어서는 서울과 경기 등 수도권이 나머지 시도에 탁월한 영향력을 미치고 있었다.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1317-1325
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• 2018

A generator-grid coupling calculation model is established to study the leading-phase operational capability of a 770 MW jumbo hydro-generator in a Chinese ultra-mega hydropower station. The static and dynamic stability of the generator are analyzed and calculated to obtain stability limits under leading-phase operating conditions. Three-dimensional (3D) time-varying nonlinear moving electromagnetic and temperature field models of the generator end-region are also established and used to determine the magnetic field, loss, and temperature of the end-region under the leading-phase operating condition. The simulation results agree with data measured from the actual 770 MW hydro-generator. This paper provides reliable reference data for the leading-phase operation of a jumbo hydro-generator, which will help to improve in the design and manufacture of future hydro-generators.

• Restorative Dentistry and Endodontics
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• 제40권2호
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• pp.123-127
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• 2015

Objectives: Glide path preparation is recommended to reduce torsional failure of nickel-titanium (NiTi) rotary instruments and to prevent root canal transportation. This study evaluated whether the repetitive insertions of G-files to the working length maintain the apical size as well as provide sufficient lumen as a glide path for subsequent instrumentation. Materials and Methods: The G-file system (Micro-Mega) composed of G1 and G2 files for glide path preparation was used with the J-shaped, simulated resin canals. After inserting a G1 file twice, a G2 file was inserted to the working length 1, 4, 7, or 10 times for four each experimental group, respectively (n = 10). Then the canals were cleaned by copious irrigation, and lubricated with a separating gel medium. Canal replicas were made using silicone impression material, and the diameter of the replicas was measured at working length (D0) and 1 mm level (D1) under a scanning electron microscope. Data was analysed by one-way ANOVA and post-hoc tests (p = 0.05). Results: The diameter at D0 level did not show any significant difference between the 1, 2, 4, and 10 times of repetitive pecking insertions of G2 files at working length. However, 10 times of pecking motion with G2 file resulted in significantly larger canal diameter at D1 (p < 0.05). Conclusions: Under the limitations of this study, the repetitive insertion of a G2 file up to 10 times at working length created an adequate lumen for subsequent apical shaping with other rotary files bigger than International Organization for Standardization (ISO) size 20, without apical transportation at D0 level.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.57-57
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• 2007

Aspheric glass lenses have many optical advantages, for glass have superior optical performance and an aspheric form can reduce optical aberrations. Recently, the use of it is rapidly expanding as the mass production becomes possible by glass molding press and so this method is considered as the best method for fabricating an aspheric glass lens, but it is difficult to control many parameters for pressing and cooling process. Design of experiments (DOE) is a very useful tool to design and analyze complicated industrial design problems. This study investigated the pressing conditions to mold aspheric glass lenses for mega pixel phone camera module using DOE method. We have applied fractional factorial design and the response variable was set form accuracy (PV) of aspheric surface of molded lens. The results of analysis indicates that all factors expect for pressing force of each step are available for the form accuracy (PV). It was the optimum condition of the designed pressing conditions for lowering the form accuracy(PV) value of molded lens that all factors were at the low level. The form accuracy (PV) of mold and molded lens under the optimum condition are $0.85\;{\mu}m$ and $0.922\;{\mu}m$ respectively.

• 대한교통학회지
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• 제26권4호
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• pp.275-285
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• 2008

"물류산업"은 장래 우리나라의 새로운 성장산업의 하나로 인식되고 있다. 그간 우리나라는 중국화물의 환적거점으로 기능을 하였으나, 최근 중국 자체항만의 성장으로 대형선단이 중국으로 이동하고 있다. 결과적으로 한국의 물류중심의 입지가 위기를 맞고 있다. 이러한 시점에서 물류혁신과 국제경쟁력 강화를 위해 새로운 전략이 필요하게 되었고, 본 연구에서는 "부가가치물류클러스터"를 새로운 전략으로 제안하고 있다. 특히 본 연구는 한국의 입지적 산업적 장점을 극대화할 수 있는 한국형 부가가치물류클러스터를 제안하고 있다. 추가적으로 한국 항만이 동북아 물류거점으로 성장할 수 있도록 한국형 부가가치물류클러스터 모형이 제안되었다. 클러스터 구성요소, 물류산업과 타 산업 간의 연관성 분석과 같은 다양한 분석과정이 한국형 부가가치물류클러스터 모형을 개발하기 위해 단계별로 시행되었다. 또한 한국형 부가가치물류클러스터 모형을 물동량 감소로 최근 위기를 맞고 있는 광양항에 적용하였다.

• 한국방사선학회논문지
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• 제4권2호
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• pp.31-35
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• 2010

본 논문에서는 방사선학과 학부생을 대상으로 국제표준단위의 기본단위와 방사선 관련단위의 인지정도에 대하여 18문항으로 이루어진 설문지를 이용하여 조사하였다. 설문조사결과 약44%의 학생들이 기본단위인 kV에 대하여 오답을 표기하였으며, 약 28%의 학생들이 km에 대하여 오답을 표기하였다. 특히 단위와 숫자와의 관계에서는 약57%의 학생들이 오답을 선택하였다. 접두어인 메가와 기가에 대해서는 각각 22%, 20%가 오답을 선택하였다. 방사선 관련단위인 Sv 또한 약 30%의 학생이 오답을 선택하였다. 방사선 관련 국제단위에 대해서는 고학년일수록 인지도가 높았다. 단위에 대해 전문적인 교육을 받았는지의 여부에 대해서는 50%가 넘는 학생들이 교육을 받지 못하였다고 하였다. 이와 같은 결과로부터 국제표준단위에 대한 교육의 필요성을 확인하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.236-236
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• 2015

Flood is one of the major natural disasters affecting millions of people. Thailand also, frequently faces with this type of disaster. Especially, 2011 mega flood in Central Thailand, inundated highway severely attributed to the failure of national economic and risk to life. Lesson learned from such an extreme event caused flood monitoring and warning becomes one of the sound mitigations. The highway flood hazard mapping accomplished in this research is one of the strategies. This is due to highway flood is the potential risk to life and limb, and potential damage to property. Monitoring and warning therefore help reducing live and property losses. In this study, degree of highway flood hazard was assessed by weighting factors for each cause of the highway flood using Multi Criteria Analysis (MCA) based Analytic Hierarchy Process (AHP). These weighting factors are the essential information to classify the degree of highway flood hazard to enable pinpoint on flood monitoring and flood warning in hazard areas. The highway flood causes were then investigated. It was found that three major factors influence to the highway flood are namely the highway characteristics, the hydrological characteristics and the land topography characteristics. The weight of importance for each cause of the highway flood in the whole country was assessed by weighting 3 major factors influence to the highway flood. According to the result of MCA analysis, the highway, the hydrological and the land topography characteristics were respectively weighted as 35, 35 and 30 percent influence to the cause of highway flood. These weighting factors were further utilized to classify the degree of highway flood hazard. The Weight Linear Combination (WLC) method was used to compute the total score of all highways according to each factor. This score was later used to categorize highway flood as high, moderate and low degree of hazard levels. Highway flood hazard map accomplished in this research study is applicable to serve as the handy tool for highway flood warning. However, to complete the whole warning process, flood water level monitoring system for example the camera gauge should be installed in the hazard highway. This is expected to serve as a simple flood monitor as part of the warning system during such extreme or critical event.

• Journal of Veterinary Science
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• 제22권6호
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• pp.67.1-67.7
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• 2021

Background: Chlamydophila felis, formerly known as Chlamydia psittaci var. felis, is frequently associated with ocular, respiratory, and occasionally reproduction tract infections. Even though the infection is sometimes asymptomatic, it potentially results in a latent immunosuppressive infection. Objective: This study aimed to identify occurrences of feline chlamydophilosis, rarely reported in cats in Indonesia. Methods: The observation was conducted in three cats with clinical signs of Cp. felis infection, particularly relapsing conjunctivitis. The cats' histories were recorded based on owners' information. Conjunctival swabs were sampled for cytology examination and molecular assay detection. A phylogenetic tree was generated using MEGA-X software to reveal group clustering. A post-mortem examination was performed on the cat that died during an examination. Results: Cp. felis was detected in both cytological examination and polymerase chain reaction assay. The phylogenetic tree demonstrated that the Cp. felis isolated in this study clustered with several other isolates from the other countries. Cp. felis can be isolated from cats with different clinical manifestations and levels of severity. The chronic fatal infection demonstrated interstitial broncho-pneumonia under histopathological examination. Conclusions: Molecular assay of Cp. felis is always recommended to obtain a definitive diagnosis of feline chlamydophilosis since the disease can have various clinical manifestations. Even though it may be subclinical and is often not fatal, an infected cat may be a carrier that could spread the pathogen in the surrounding environment. Serious disease management is suggested to avoid high costs associated with regularly relapsing disease.