• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.106-107
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• 2014

This study dealt with an experimental study on development of tile grout cement complied with international standards criteria. Tile Grout Cement is divided two grade, 1 type and 2 type, in KS F 1592:2011. International Standards(ISO) is divided 9 grade. performance evaluation for cement content was measured according to KS L ISO 13007. water absorption test results are based on the cement content 30% were satisfied with International Standards criteria. strength test results are based on the cement content 25% were satisfied with International Standards criteria.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.234-239
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• 2003

디지털방송, DAB 등과 같은 디지털 오디오 방송 서비스를 위한 디지털 시스템을 설계하기 위해서는 오디오 음질을 평가하기 위한 방법이 필수적이다. 기존의 방식은 인간의 귀를 이용한 주관적 방식을 이용함으로서 많은 시간과 비용을 들이게 되며, 음질평가를 하는 사람의 주관적 의견에 많이 좌우하게 된다. 그러나 최근 ITV-R에서는 오디오 음질의 객관적 평가를 위한 BS.1387(PEAQ)를 제안함으로 많은 시간과 비용을 절감하고 신뢰할 수 있는 결과를 얻게 되었다. PEAQ는 인간의 귀에서의 신호의 처리과정과 인식과정을 심리음향모델과 인식모델로 분리하여 구성함으로써 주관적 평가의 SDG(Subjective Difference Grade)에 대응하는 ODG(Objective Difference Grade)를 구하게 된다. 본 논문에서는 이러한 PEAQ의 심리음향 모델과 인식 모델을 원리와 과정을 평가 분석하였다.

• Journal of The Korean Association For Science Education
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• v.23 no.4
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• pp.430-441
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• 2003

The purpose of this study was to investigate the effects of students' prior knowledge on scientific reasoning in solving a pendulum task with a computer simulation. Subjects were 60 Korean students: 27 fifth-grade students from an elementary school and 33 seventh grade students from a middle school located in a city with 300,000 people. This study adapted a pendulum task presented with a computer simulation on which subjects would use a pattern of multivariable causal inferences. The subjects were interviewed individually in a three-phase structured interview by the researcher and three assistants while he/she was investigating the pendulum task. This study showed that most students across grades focused heavily on demonstrating the primacy of their prior knowledge or their current hypothesis. In addition, students' theories that are part of one's prior knowledge have a significant impact on formulating, testing, and revising hypotheses. Therefore, this study supported the notion that students' prior knowledge had a strong effect on students' experimental intent and hypothesis evaluation.

• Proceedings of the KSMRM Conference
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• 2003.10a
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• pp.24-24
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• 2003

Purpose： It is known that diffusion-weighted MR imaging (DWI) is helpful in the evaluation of malignancy grading in brain tumor. This study was to evaluate the DWls with different b-values of various brain tumors in order to determine optimal b-values on 3T MR unit. Method： On a 3T MR unit, DWls with b-values of 1, 000, 3, 000 and 5, 000 s/mm2 were obtained in 20 patients of pathologically-proven brain tumors (7 metastases, 4 high grade gliomas, 2 Iymphomas, 2 low grade gliomas, 2 germinomas, and one each of germinoma, meningioma, hemangioblastoma and central neurocytoma. The overall image quality, contrast between normal brain parenchyma and tumor and signal intensities of solid and cystic components were comparatively evaluated among DWls with different b-values by visual inspection.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.37-38
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• 2016

In this study, it evaluate the coarse aggregate mixed effect to impact resistance performance of the fiber reinforced cement-based material. The type of fiber is Hooked-ended steel fiber, and mixed 1vol.% in concrete and cement composites. The impact experiment was conducted by using a spherical shape projectile diameter of 25mm to 170m/s speed and Impact resistance performance was evaluated by measuring the fracture grade, fracture diameter and depth.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.124-130
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• 1995

연삭작업에 있어서 요구되는 가공능률과 가공정밀도를 얻기 위해서는 적절한 결합도를 갖는 연삭숫돌을 선택하 는 것이 중요한 요건이 된다. 본 연구에서는 결합도를 평가하기 위한 일정한 기준을 설정할 목적으로 AE계측 시스템을 이용하여 대월식결합도시험방법에 따라 연삭숫돌표면의 일부를 파괴시켰을 때 발생되는 AE신호를 검출 하고 연삭숫돌의 파괴량과 AE 신호특성과의 관계 및 AE를 이용한 결합도평가의 가능성을 검토하였다.

• Journal of Korean Elementary Science Education
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• v.27 no.3
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• pp.261-272
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• 2008

This study focused on explicitly instructional effects about NOS(Nature of Science) of sixth grade students. Participants were 28 sixth grade students. Data sources included classroom observations of the explicit NOS science lessons, questionnaire, and interviews. 5 students among the participants were selected for the interviews. Date were analyzed for finding the changes of students' thoughts. Before the instruction, the majority of participants held naive views of NOS, but after the instruction, the majority of participants held informed views of NOS. Developing informed conception of NOS within curriculum is necessary to growth of science education.

• Journal of the Korea Furniture Society
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• v.13 no.2
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• pp.11-18
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• 2002

This study was carried out to investigate the strength and technical feasibility of glulam from small diameter Pinus densiflora and Larix kaempferi. Small diameter logs are currently not used in structural laminated beam construction, but it is suggested that its properties may be feasible for this purpose. The glulam combinations were designed with high grade laminae located at outer laminations (face) and low grade laminae located at center laminations. Important problems of finger jointed glulam as a structural beam are the small modulus of rupture (MOR). One solution for this problem Mi to use veneer and solid wood as the face laminae. The MOE values were predicted for each beam from laminae. The results showed that actual beam MOE values exceeded slightly the predicted values. Based on the evaluation and analysis of Pinus and Larix glulam, the maximum load of Larix kaempferi glulam indicated large values. The bending properties of A and E types glulam were superior to others. It is suggested that this small diameter log can be a candidate for structural glulam construction, providing the proper combinations of face laminae.

• Journal of the Society of Disaster Information
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• v.6 no.1
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• pp.10-24
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• 2010

In this paper, warm asphalt binder was proposed as a substitute for the polymer-modified asphalt binder to get higher viscosity than that of the polymer-modified at the same temperature. Performance grade test and rotational viscosity of warm asphalt binder were conducted to evaluate the property variations due to the addition of admixture. Research results showed that the viscosity of warm asphalt binder at $100^{\circ}C$ was similar to that of the conventional asphalt binder. The performance and durability of warm asphalt binder were also comparable to those of the polymer-modified. It is considered that the active applications of warm asphalt binder can reduce environmental damages due to less diffusions of carbon dioxide compared to the conventional.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.16-17
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• 2020

The Temporary construction refers to the construction or dismantling of temporary structures installed for the construction of the main structure at the construction site, and the members constituting this temporary facility are called temporary equipment. Temporary equipment used in construction sites is mostly used products that are reused rather than new products, and it is necessary to consider performance degradation due to repeated use. This study is a preliminary study to develop the performance evaluation criteria applied to temporary equipment that is distributed and reused for secondhand. This study is to analyze the performance status of temporary equipment of used goods owned by rental companies by condition grade through performance tests.