• Journal of the Korean Society for Nondestructive Testing
• /
• v.31 no.5
• /
• pp.500-507
• /
• 2011

Acoustic emission(AE) signals during the polymerization shrinkage of composite resin subjected to the LED light exposure were detected through a wave guide method and a direct sensor attachment method. For PMMA, human tooth, stainless steel substrate, data of AE hits and amplitudes were compared. For the test using the wave guide, AE amplitudes decreased because of the attenuant wave. However, AE hits and 1st peak frequency distribution were not different according to the sensor attachments. Through the experiments, wave guide could be used for a nondestructive evaluation of the marginal disintegrative fracture of dental restoration.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.20-21
• /
• 2017

There have been reports in the media about some refineries that omit the refining process and deliver raw material for reasons of cost reduction, shortening of production time, etc. Also, in most RMC factories acceptance inspection is not conducted on account of issues with the proficiency of the equipment and cost issues; instead only scores are relied upon. Therefore this study sought to analyze the relation between the value of the density of FA actually delivered to RMC companies, attained with the Hydrometer method, and its fineness, to see whether the quality of FA can be evaluated statistically. Results led to the conclusion that there is a problem in terms of credibility in the fineness of FA shown on the test report. Upon analyzing the difference between the fineness of FA as measured using Blaine's air permeability method and its density of the Hydrometer method, the correlation was found to be satisfactory; therefore the possibility of a FA fineness quality evaluation could be proved as well.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.27 no.6
• /
• pp.563-575
• /
• 2007

This contribution contained the classical work of an open-hole tensile plate to demonstrate the performance of grating shearography and to compare with the results obtained by other full-field measurement techniques, The isotropic plate with an open-hole has often appeared in the previous contributions introducing novel full-field method and system. Grating shearography directly provided six quantitative measurands about the specimen's surface kinematics by using a single measurement set: three in-plane strains, in plane rotation, and two out-of-plane slopes. The quasi-plane wavefront of grating metrology led to high signal-to-noise ratio (SNR) and thus neither fitting nor filtering was applied, and the small shearing distance of $101{\mu}m$ could be used. The small shearing distance provided the outstanding spatial resolution of $80{\mu}m$ and sensitivity appropriate for experimental mechanics. Finally, the grating shearography enabled the visualization of the complex surface deformation around the hole and also detected parasitic flexions of the specimen in the micrometer regime during the tensile test.

• Horticultural Science & Technology
• /
• v.31 no.6
• /
• pp.821-827
• /
• 2013

The purpose of this study was to investigate the effects of three kinds of horticultural activities (HAs) on attention concentration of elementary students. We selected 20 students using a Wee Class counseling office at J elementary school in Yeongcheon, and divided them into experimental and control groups composed of ten students each. The experimental group participated in three HAs including flower arrangement, planting, and pressed flower. Each HA was composed of three sessions and a session proceeded for a week. For the examinations of attention concentration, two groups responded the questionnaires before a week of the first session and at the end of the 9th session, only the experimental group participated in the measurement using grid by Harris before a week of the first session and at the end of each HA every week. The results of questionnaire survey showed that the scores of problem in emotion and problem in controlling, and the total score decreased 9.2, 7.8, and 19.0 points, respectively (P < 0.05), indicating that the attention concentration of the experimental group improved compared with the control. In the measurements using grid by Harris, the flower arrangement, planting, and pressed flower activities increased the scores by 2.22, 2.49, and 2.41 points compared with the pre-HA of 6.00, respectively (P < 0.05), that means the improvements of attention concentration. At the post-HAs, the flower arrangement, planting, and pressed flower activities increased the scores by 1.12, 1.39 and 1.31 points compared with the control group of 7.10, respectively (P < 0.05). In conclusion, the indoor HAs improved the attention and concentration of elementary students irrespective of kind of activities.

• Journal of The Korean Association For Science Education
• /
• v.27 no.1
• /
• pp.18-27
• /
• 2007

This study examined the influences of cognitive conflict and non-cognitive variables induced by a discrepant event on process of conceptual change, and the processes that a discrepant event lead to situational interest. Seventh graders participated in this study. A preconception test was administered to select students possessing misconceptions about density. The tests of cognitive response and situational interest to a discrepant event were administered. After learning with a CAl program, the tests assessing attention and effort allocated to the CAl, and conceptual understanding were also administered. A path analysis revealed that cognitive conflict induced by a discrepant event caused situational interest, which in turn increased attention and/or effort and thus, resulted in conceptual change. The results of the path analysis on the processes in which a discrepant event led to situational interest suggested that novelty may be a primary source of situational interest. Novelty influenced situational interest directly as well as through attention demand, exploration intention, and instant enjoyment. Moreover, novelty exerted a direct effect on challenge, which in turn had negative effects on instant enjoyment directly as well as through cognitive conflict, and thus, decreased situational interest. However, the path coefficients of the latter were relatively smaller than those of the former. Educational implications are discussed.

• Korean Journal of Clinical Laboratory Science
• /
• v.47 no.3
• /
• pp.125-131
• /
• 2015

The discovery of activating mutations in EGFR in a subset of lung adenocarcinomas was a major advance in our understanding of lung adenocarcinoma biology, and has led to groundbreaking studies that have demonstrated the efficacy of tyrosine kinase inhibitor therapy. Cytologic specimen procedures have become increasingly popular for obtaining diagnostic material in lung carcinomas. However, frequently the small amount of material or sparseness of tumor cells obtained from cytologic preparations limit the number of specialized studies, such as mutation analysis, that can be performed. In this study we used microdissection to isolate small numbers of tumor cells to assess for EGFR mutations from 76 cytological smear slides of patients with lung adenocarcinomas. We compared our results with previous molecular assays that had been performed on either surgical or cytology specimens as part of the patient's initial clinical work-up. Not only were we able to detect the identical EGFR mutation through the pyrosequencing, but we were also able to consistently detect the mutation from as few as 25 microdissected tumor cells. Furthermore, isolating a purer population of tumor cells resulted in increased sensitivity of mutation detection as we were able to detect mutations from microdissection-enriched cases. Therefore, microdissection can not only significantly increase the number of lung adenocarcinoma patients that can be screened for EGFR mutations, but can also facilitate the use of cytologic samples in the newly emerging field of molecular-based personalized therapies.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2017.04a
• /
• pp.146-146
• /
• 2017

현대의 스마트폰 및 태블릿pc등을 가능하게 만든 집적 기술 중의 하나는 3차원 집적 회로(3D-IC)와 같은 패키징 기술이다. 이러한 첨단 3차원 집적 기술은 메모리집적을 통한 대용량 메모리 모듈 개발뿐만 아니라, 메모리와 프로세서의 집적, high-end FPGA, Back side imaging (BSI) 센서 모듈, MEMS 센서와 ASIC 집적, High Bright (HB) LED 모듈 등에 적용되고 있다. 3D-IC의 3차원 모듈 제작 시에는 기존에 발생하지 않았던 여러 가지 파괴 모드들이 발생하고 있는데 Thermal/Photonic Emission 장비 등 기존의 2차원 결함분리 (Fault Isolation) 기술로는 첨단의 3차원 적층 제품들에서 발생하는 불량을 비파괴적으로 혹은 3차원적으로 분리하는 것이 불가능하므로, 비파괴 3차원 결함 분리 기술은 향후 선행 제품 적기 개발에 매우 필수적인 기술이다. 본 연구는 3D-IC 반도체의 비파괴적 내부결함 검사를 위하여 가시광선-근적외선 대역(351nm~1770nm)의 InGaAs (Indium Galium Arsenide) 계열 영상검출기 (imaging detector)를 사용하여 분광 시스템 광학 설계를 통한 초분광 영상 기반 검출 모듈을 제작하였다. 제작된 초분광 영상 기반 검출 모듈을 이용하여 구리 회로 위에 실리콘 웨이퍼가 3단 적층 된 반도체 더미 샘플의 초분광 영상을 촬영하였으며, 촬영된 초분광 영상에 대하여 Chemometrics model 기반의 분석기술을 적용하여 실리콘 웨이퍼 내부의 집적 구조에 대한 검사가 가능함을 확인하였다.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.1 no.1
• /
• pp.31-39
• /
• 2008

After the introduction of ultrasound enabling a detailed view of both neonatal hip instability and morphology, two different streams have developed: one arguing that neonatal hip instability is the major pathology warranting treatment, the other including acetabular dysplasia as an important feature. Graf's method including the acetabular dysplasia led to higher treatment and follow-up rate than that based upon neonatal hip instability only. Recent report suggested that improved examination techniques and a better understanding of the findings have enabled a more tailored approach, and no differences in treatment rates exist due to different ultrasound techniques. I'd like to emphasize that enough experiences and the understanding enabling standardized examination and high repeatbility is more important than the choice of different techniques. Here the mothods and meanings of different techniques of ultrasound and its usefulness in the diagnosis and treatment of DDH is discussed.

• Applied Biological Chemistry
• /
• v.41 no.2
• /
• pp.166-174
• /
• 1998

The effects of some organic acids on the shelf life of cooked noodle and the change in textural properties were studied. Organic acids used were vinegar, lactic, citric and malic acid. The pH of noodle was adjusted to $4.7{\pm}0.25$ by dipping it in each solution for 30 seconds. Total microbial count and turbidity of the treated samples were measured storage for 4 days at $15^{\circ}C$. The total count was high in order of control, malic, citric, lactic acid and vinegar. High turbidity was observed in order of control, lactic, malic, citric acid and vinegar. Hardness, adhesiveness, cohesivenes and springiness were measured for 30 days at $35^{\circ}C$ using Rheometer along with concurrent sensory evaluation. The acid treated samples showed higher values in hardness and cohesiveness than control but lower in adhesiveness and springiness. After 30 days storage, the malic or citric acid treated sample led to a somewhat higher gumminess than control. Based on the sensory evaluation the malic acid treated noodle significantly exhibited the highest score followed by citric, lactic acid, control and vinegar.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.2
• /
• pp.205-210
• /
• 2005

As industries developed, industrial goods have got more precise. It led producers to feel like having a way to confirm whether the goods are good enough for the needs of consumers or not. Because of that, producers got interested in industrial photogrammetry that can get accurate data quickly with non-confect method. therefore, this study was examined by photographing an O-2A aircraft which was a large and precise one to check the application of Industrial photogrammetry. To measure the aircraft, the check points, that was attached to it was used as it was not possible to measure the aircraft by its design. The experiment was carried out in three parts considering arrangement of the check points and measured with Pro-spot to check any deformation of its external form. As a result, this study enables us to conferm a state of the aircraft alignment promptly and to provide accurate data for producers, which helps them to make a decision.