• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
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• pp.15-25
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• 2007

Gravity method could be one of the most effective tool for evaluating the soundness of basement which is directly correlated with density and its variations. Moreover, Gravimeter is easy to handle and strong to electromagnetic noises. But, gravity anomaly due to the target structures in engineering and environmemtal applications are too small to detect, comparing to the external changes, such as, elevation, topography, and regional geological variations. Gravity method targeting these kinds of small anomaly sources with high precision usually called microgravity. Microgravimetry with precision and accuracy of few ${\mu}Gal$, can be achieved by the recent high-resolution gravimeter, careful field acquisition, and sophisticated processing, analysis, and interpretation routines. This paper describes the application of the microgravity, such as, density structure of a rock fill dam, detection of abandoned mine-shaft, detection and mapping of karstic cavities in limestone terrains, and time-lapse gravity for grout monitoring. The case studies show how the gravity anomalies detect the location of the targets and reveal the geologic structure by mapping density distributions and their variations.

• 디지털융복합연구
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• 제10권4호
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• pp.347-352
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• 2012

자연의 불확정적인 물리현상은, 감성적인 공학기술 영역뿐 아니라 및 예술의 시각표현 방법으로도 자주 연구되는 영역이다. 본 논문에서는 모더니즘 회화에서 물질의 특성을 강조한 회화작품에서 보여 지는 자연의 물리적인 현상들(스며듦, 번짐, 흐름)을 분석한 연구[1]를 Unity3D 엔진의 파티클 시스템을 이용하여 구현 가능성을 제안한다. 그리하여 그래픽스 프로그래밍 습득에 어려운 아티스트들이 수월하게 Unity3D 엔진을 이용하여 자연의 불확정적 비주얼표현 구현에 도움을 줄 수 있으며 또한 감성기반 테크놀로지를 연구하는 공학자들에게도 아이디어 제공에 도움을 줄 수 있을 것이다.

• East Asian mathematical journal
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• 제36권2호
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• pp.229-251
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• 2020

Problem Based learning(PBL) is a teaching and learning method to increase mathematical ability and help achieving mathematical concepts and principles through problem solving using the learner's mathematical prerequisite knowledge. In addition, the recent instructional situations or environments have focused on the learner's self construction of his learning and its process. In spite of such a quite attention, it is not easy to apply and execute PBL program actually in class. Especially, there are some difficulties in actually applying and practicing PBL in the areas of mathematics education in not only secondary school but also in college. Its reason is that in order to conduct PBL instruction constantly in real or experimental class there is no more concrete and detailed instructional content during the consistent and long period. However, to whom is related to mathematics education including instructors called scaffolders, investigation and recognition on the degree of the learner's acquisition of mathematical thinking skills and strategies is an very important work. By the reason, in this study, the instructional content was to be explored and developed to be conducted during 15 weeks in one semester, which was based on Problem Based Learning environment by the subject of the theories relevant to mathematics education in the college of education.

• 한국추진공학회지
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• 제13권6호
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• pp.1-7
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• 2009

가스터빈 엔진의 성능은 그 구성품 성능 특성에 큰 영향을 받는다. 보통 이러한 구성품 성능 특성은 여러 조건에서의 수많은 실험을 통해 얻을 수 있지만 그것은 제작사의 고유 재산이기 때문에 쉽게 제공되지 않는다. 그렇기 때문에 보통 성능 덱을 이용하거나 소유하고 있는 엔진 성능 맵을 스케일링 하여 사용한다. 하지만 이러한 방법은 탈설계점에서 오차를 보인다. 이에 본 연구에서는 소형 가스터빈 엔진 실험 장치를 구성하여 몇 구간에서의 실험을 통해 데이터를 축적하고 이를 이용하여 구성품 성능 맵을 축척하는 방법을 제시하였다. 그리고 프로그램을 이용하여 대상 엔진의 정상상태 성능 모델을 구성하여 실제 측정 데이터와 새롭게 생성된 구성품 맵을 사용했을 경우, 그리고 기존의 방법을 이용한 경우를 비교하였다.

• 수산해양교육연구
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• 제26권3호
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• pp.485-491
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• 2014

The study of Web MGIS(Marine Geographic Information System) based on the SVG(Scalable Vector Graphics) is mainly performed on effective methodologies which transform real world data to computing world data. Web GUI system has its own target on reliable data service by acquisition of geometric information using HYCOM(HYbrid Coordinate Ocean Model), accurate measurement and graphical visualization. This type of raw data visualization can be built without software tools, yet is incredibly useful for interpreting and communicating data. Even simple visualizations can aid in the interpretation of complex hydrodynamic relationships that are frequently encountered in the marine environment. The Web MGIS provides an easy way for hydrodynamic geoscientists to construct complex visualizations that can be viewed with free software. This study proposes a Web GUI MGIS using FVCOM(Finite Volume Coastal Ocean Model). Finally, we design a Marine Web GUI system of Kosrae Coastal Waters integrating above data models. It must adds more ecological information and the various service item for approach more easily in order to user.

• 대한치과보철학회지
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• 제44권2호
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• pp.243-249
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• 2006

Statement of problem: It is important to have a correct presurgical treatment plan before any implant surgery. It must contain substantial information about the patient concerned. However, the standard classification only notifies the dentist about various structural, pathological and physiological dimensions Due to diverse structure of the jaw bone, current standard classification does not tell spatial dimensions of the available bone for implant insertion sites. Purpose of study: The purpose of this study is to report the establishment of the systematic implant treatment plan and its clinical treatment using $Implan^(R)$ program which is based on ASCIi-classification that is available for future diagnosis and scale of treatment and for systematic implant insertion. Results: By assisting the systemic measurement of the available alveolus dimension during implant surgery, it was easy to set initial implant treatment plan. Conclusion: Using $Implan^(R)$ program which is based on ASCIi-classification system that allows the establishment of systemic implant treatment plan and successful clinical performance, it was possible to establish the founding or initial implant treatment plan , the acquisition of information, and the systematization of documentation.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.50-56
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• 2013

Optical-fiber electronic speckle pattern interferometry (ESPI) is a non-contact, non-destructive examination technique with the advantages of rapid measurement, high accuracy, and full-field measurement. The optical-fiber ESPI system used in this study was compact and portable with the advantages of easy set-up and signal acquisition. By suitably configuring the optical-fiber ESPI system, producing an image signal in a charge-coupled device camera, and periodically modulating beam phases, we obtained phase information from the speckle pattern using a four-step phase shifting algorithm. Moreover, we compared the actual defect size with that of interference fringes which appeared on a screen after calculating the pixel value according to the distance between the object and the CCD camera. Conventional methods of measuring defects are time-consuming and resource-intensive because the estimated values are relative. However, our simple method could quantitatively estimate the defect length by carrying out numerical analysis for obtaining values on the X-axis in a line profile. The results showed reliable values for average error rates and a decrease in the error rate with increasing defect length or pressure.

• Earthquakes and Structures
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• 제17권1호
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• pp.63-73
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• 2019

This paper studies damage detection as an optimization problem. A new objective function based on changes in natural frequencies, and Natural Frequency Vector Assurance Criterion (NFVAC) was developed. Due to their easy and fast acquisition, natural frequencies were utilized to detect structural damages. Moreover, they are sensitive to stiffness reduction. The method presented here consists of two stages. Firstly, Finite Element Model (FEM) is updated. Secondly, damage severities and locations are determined. To minimize the proposed objective function, a new bio-inspired optimization algorithm called salp swarm was employed. Efficiency of the method presented here is validated by three experimental examples. The first example relates to three-story shear frame with two single damage cases in the first story. The second relates to a five-story shear frame with single and multiple damage cases in the first and third stories. The last one relates to a large-scale eight-story shear frame with minor damage case in the first and third stories. Moreover, the performance of Salp Swarm Algorithm (SSA) was compared with Particle Swarm Optimization (PSO). The results show that better accuracy is obtained using SSA than using PSO. The obtained results clearly indicate that the proposed method can be used to determine accurately and efficiently both damage location and severity in multi-story shear frames.

• 한국축산식품학회지
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• 제41권5호
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• pp.816-825
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• 2021

This study aims to validate a fast method of simultaneous analysis of 365 LCamenable and 142 GC-amenable pesticides in hen eggs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively, operating in multiple reaction monitoring (MRM) acquisition modes. The sample preparation was based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction. Key method performance parameters investigated were specificity, linearity, limit of quantification (LOQ), accuracy, precision and measurement uncertainty. The method was validated at two spiking levels (10 and 50 ㎍/kg), and good recoveries (70%-120%) and relative standard deviations (RSDs) (≤20) were achieved for 92.9% of LC-amenable and 86.6% of GC-amenable pesticide residues. The LOQs were ≤10 ㎍/kg for 94.2% of LC-amenable and 92.3% of GC-amenable pesticides. The validated method was further applied to 100 egg samples from caged hens, and none of the pesticides was quantified.

• Journal of Information Processing Systems
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• 제17권6호
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• pp.1179-1190
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• 2021

A data acquisition and monitoring system was developed for an automated system of a smart fish farm. The fish farm is located in Jang Hang, South Korea, and was designed as circulation filtration system. Information of every aquaculture pool was automatically measured by pH sensors, dissolved oxygen sensors, and water temperature sensors and the data were stored in the database in a remoted server. Modbus protocol was used for gathering the data which were further used to optimize the pool water quality to predict the rate of growth and death of fish, and to deliver food automatically as planned by the fish farmer. By using JSON protocol, the collected data was delivered to the user's PC and mobile phone for analysis and easy monitoring. The developed monitoring system allowed the fish farmers to improve fish productivity and maximize profits.