• Journal of The Korean Association For Science Education
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• v.39 no.3
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• pp.405-414
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• 2019

As a case study, we analyzed the professor's teaching professionalism in college of science-engineering based on pedagogical content knowledge. Two professors from the college of science-engineering located in Chungcheongbuk-do participated in this study. After collecting their syllabi, we observed their classes and conducted semi-structured interview before and after the classes. Analysis were conducted on their syllabi, taped videos, field notes and transcripts of the interview. As a result, both professors' orientation to teaching was not only related to learning subject matter knowledge, but also developing job competencies or communication skills. Their orientations were transformed according to the educational situation. After establishing the final learning goals, the professors organized weekly plan by listing the topics. However, they were unaware that the goals of each topic should be presented in detail in the class. Also, one of them presented a lack of understanding of the students' prior knowledge and showed low understanding of what aspects of the topics make students difficult to learn. In addition, the two professors applied various teaching strategies such as giving examples, questioning, and problem solving, but the degree of students' participation was not enough in the process of teaching. In the aspect of assessment, the professors had low understanding in students' achievement or feedback. Based on the results of the analysis, this study proposed methods and strategies for improving the teaching professionalism of science-engineering professors.

• Journal of Life Science
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• v.29 no.6
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• pp.705-711
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• 2019

Benign prostatic hyperplasia (BPH) is the most common urogenital disorder in men, benign tumor and is a typical disease deteriorating the quality of old men's lives, and its prevalence increases with age. Though the molecular pathogenesis of BPH has not yet been clearly revealed, it is known that the variation and aging of the endocrine including sex hormone may cause BPH. Especially the hypertrophy of the prostate cell by the formation of the excessive dihydrotestosterone (DHT) is estimated to cause BPH. If testosterone exists excessively in blood, a lot of DHT is produced in prostate by $5{\alpha}-reductase$. Thus, in this study we tried to analyze haematological change and histopathological change by using the model rat with BPH caused by hypodermic injection of testosterone to prove the effect of Houttuynia cordata extracts on BPH. Rats were divided into four experimental groups: no treatment group (N), the testosterone injection and D.W treatment group (DO), the testosterone injection and Houttuynia cordata treatment group (HO) and testosterone injection and finasteride treatment group (FO). Prostate weight, volume and weight ratio in the HO and FO groups were significantly lower than the DO group. Testosterone and DHT levels in the HO group were significantly lower than the DO group. The HO and FO groups showed trophic symptoms and were lined by flattened epithelial cells, thus, the stromal proliferation is relatively low as compared to the DO group. These results suggest that Houttuynia cordata may control benign prostatic hyperplasia.

• The Korean Journal of Archival Studies
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• no.25
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• pp.91-129
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• 2010

As it grows more heavily reliant on information system, researchers seek for various ways to manage and utilize of dataset records which is accumulated in public information system. It might be needed to adjust date and enhance the quality of public administrative dataset records during transferring to archive system or sharing server. The purpose of this paper is presenting data adjustment and quality enhancement methods for public administrative dataset records, and it refers to ETT procedure and method of construction of datawarehouses. It suggests seven typical examples and processing method of data adjustment and quality enhancement, which are (1) verification of quantity and data domain (2) code conversion for a consistent code value (3) making component with combinded information (4) making a decision of precision of date data (5) standardization of data (6) comment information about code value (7) capturing of metadata. It should be reviewed during dataset record transfer. This paper made Data adjustment and quality enhancement requirements for dataset record transfer, and it could be used as data quality requirement of administrative information system which produces dataset.

• Economic and Environmental Geology
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• v.51 no.6
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• pp.579-587
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• 2018

Chungnam Basin has been known as one of the largest Mesozoic basins in Korea, filled mainly with so-called Daedong Supergroup. The basin has evolved as the Early to Middle Jurassic intra-arc volcano-sedimentary basin developed on top of the Late Triassic to Early Jurassic post-collisional basin in this area, recording evolutionary history of the Mesozoic tectonics in the southwestern Korean Peninsula. This study carries out the geometric interpretations of the Seongjuri syncline and its surroundings in the central part of the Chungnam Basin, based on detailed structural field survey. Based on its doubly-plunging fold geometry, the Seongjuri syncline could be subdivided into the southwestern and northeastern domains. On the down-plunge profiles of the southwestern domain of the Seongjuri syncline as well as the underlying Okma fold, the Okma fault shows typical geometry of a basement-involved reverse fault that propagated up to the sedimentary cover. The profiles illustrate that the Seongjuri syncline occurs in front of the tip of the Okma fault, likely implying its origin as a part of the fault-related fold system. The result of this study will provide better insight into the structural interpretation of the Chungnam Basin, and will further provide useful information for the Mesozoic orgenic events of the southwestern Korean Peninsula.

• Journal of Conservation Science
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• v.34 no.6
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• pp.493-502
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• 2018

Currently, the fabrication of a high-tin bronze spoon by traditional manufacturing techniques involves 10 steps in the bronze ware workshop. Hot forging has a major influence on manufacturing and involves two to three steps. The dendritic ${\alpha}$-phase in the microstructure of the high-tin bronze spoon is refined and finely dispersed through hot forging. In addition, twinning is observed in the ${\alpha}$-phase of the hammered part, and the ${\alpha}$-phase microstructure gradually transform from a polygon to a circular shape due to hammering. In this process, the adjacent ${\alpha}$-phases overlap with each other and remain combined after quenching. The microstructure with the overlapping is also observed in bronze artifacts, and this shows the correlation with technical system. The results of the experimental hot forging of Cu-22%Sn alloys show that the decrease in in the amount of the dendritic microstructure, which forms during casting, is in proportion to the number of processing steps and that the refined grain obtained by hammering contributes to the improvement in the strength of the material. From the hammering marks, which are observed on both the bronze artifact excavated from archaeological sites and on the high-tin bronze spoon produced in the traditional workshop, it is presumed that the knowledge regarding the unrecorded manufacturing system of bronze ware in ancient times has been passed down in a traditional way up to the system used currently.

• Journal of the Korean Geotechnical Society
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• v.34 no.12
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• pp.93-103
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• 2018

Behaviors of splices between bolts and welding spliced PHC piles using the tensile strength test were analyzed. The bolts spliced PHC piles, which were tightened over $200N{\cdot}m$ tightening torque, showed straight V shaped line at splices at the lowest 20 N load. Both sides of PHC piles stayed straight, so the full section of bolts spliced piles did not show the unifying behavior, which was the most important performance requirement as pile. Other bolts spliced PHC piles, tightened with $20N{\cdot}m$ loosening torque, also showed the same straight V shaped line at splices for each step of loading. The full section of bolts spliced piles did not return to the initial position after each step of unloading and did not show the elastic material behavior. The splices quality of bolts spliced piles is much lower than that of welding spliced piles with respect to displacement of splices during each step of loadings, residual displacements during each step of unloadings, and failure loads. Results showed that bolts spliced PHC piles, tightened with both over $200N{\cdot}m$ and as low as $20N{\cdot}m$ torque, fell short of performance requirements of spliced PHC pile.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.24-47
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• 2013

This study focused on the constructional concepts, landscape design techniques and changes made of the Sandan(山壇) area in the rear garden of Changdeokgung Palace based on the spatial organization of the zone. The results of this study are as below. Constructional layers that have been maintained throughout the centuries from King Injo(仁祖), King Sukjong(肅宗), King Sunjo(純祖), the Japanese colonial period to the present, were found in the Sandan area. The Sandan area, which was developed with the establishment of Chuiseungjeong(取勝亭) during the ruling of King Injo(仁祖), was created as a resting place for the King, and its usage continued until King Sukjong(肅宗) built Nakminjeong(樂民亭). However, the whole area was reorganized to host ritual ceremonies, where ancestral rites were performed for the mountain gods, after Sandan and Baekunsa(白雲社) were built during King Gojong's reign, before the drawing of 'Painting of Eastern Palaces(東闕圖).' The architectural component used then appears to have been designed to serve ancestral ritual formalities for the god of land, or to satisfy the religious desires of the royal family not fulfilled by Confucian courtesy. These are characteristics that define the Sandan area. Meanwhile, the analysis of the ground plan of the Changdeokgung Palace revealed that the Sandan had been maintained until the Japanese colonial era, but was removed sometime after liberation. The area underwent extensive reform in the early 1970s, when the whole area was developed into a tourist destination called Bingcheon(氷泉). Then, a new road that runs through Bingcheon was laid, and the present condition reflects the construction result of the time. An interview with a person who had taken part in the repair work in the 1970s confirmed that the construction work at the time had the goal of establishing two drainage systems for drinking water and copied the Okryuchon(玉流川) well.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.4
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• pp.425-433
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• 2019

In this paper, the RCS analysis of the 10m unmanned surface vehicles was performed, and the factors of RCS increase were analyzed. Modeling techniques by transforming a geometric shape can reduce the RCS area, which can be used to develop stealth unmanned surface vehicles. In order to reduce the RCS, the existing Top Mast part was moved 1m to the tail part, the 5 degree tilt angle was moved below 0.5 m, and additional guided walls were installed to minimize the influence on the center and surrounding corner reflecting structures. As a result of comparing and analyzing the RCS analysis value with the existing model, it can be seen that the reduced countermeasure model is -3.79 dB lower than the existing model for all elevations. In particular, it can be seen that the strong scattering phenomenon is substantially removed in the region except the sacrificial angle region. In addition, it can be seen that in the case of -5m to 2m where the guide wall is added, the reflected signal is improved up to 20 to 40 dB or more, so that it does not appear on the 2D ISAR image. RCS analysis of unmanned surface vehicles explained the process of analyzing and identifying problem location through distance profile analysis and ISAR image analysis.

• Journal of the Korea Institute of Building Construction
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• v.19 no.3
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• pp.209-217
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• 2019

EMP (Electromagnetic Pulse) usually means High Power Electromagnetic Wave (HPEM). In the case of the shielding plate against the EMP, there is a possibility of deterioration of the electromagnetic wave shielding performance due to the skill of the constructor, bad construction, deformation of the shielding plate at the connection portion (joint portion). The inefficient use of space due to the separation distance is also pointed out as a problem. Therefore, this study aims to derive the optimum electromagnetic shielding condition by applying ATMSM to concrete as a part of securing electromagnetic wave shielding performance with reflection loss against concrete wall. Experimental parameters included concrete wall thickness and application of Zn-Al ATMSM. For the concrete wall, the wall thickness was 100 to 300mm, which is generally applied, and experimental parameters were set for the application of Zn-Al metal spraying method to evaluate electromagnetic shielding performance. Experimental results showed that as the thickness increases, the electromagnetic shielding performance increases due to the increase of absorption loss. In addition, after the application of Zn-Al ATMSM, the average shielding performance increased by 56.68 dB on average, which is considered to be increased by the reflection loss of the ATMSM. In addition, it is considered that the shielding performance will be better than that when the conductive mixed material and the ATMSM are simultaneously applied.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.2
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• pp.61-70
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• 2019

Geopolymer is an eco-friendly construction material that has various advantages such as reduced $CO_2$ emission, fire resistance and low thermal conductivity compared to cement. However, it has not been many studies on the thermal behavior of the surface of the geopolymer panel when flame is applied to the surface. In this study, surface characteristics of hardened geopolymer on flame exposure was investigated to observe its characteristics as heat-resistant architectural materials. External structure changes and crack due to the heat shock were not observed during the exposure on flame. According to the residue of calcite and halo pattern of aluminosilicate gel, decarboxylation and dehydration were extremely limited to the surface and, therefore, it is thought that durability of hardened geopolymer was sustained. Gehlenite and calcium silicate portion was inversely proportional to quartz and calcite and significantly directly proportional to BFS replacement ratio. Microstructure changes due to the thermal shock caused decarboxylation and dehydration of crystallization and it was developed the pore and new crystalline phase like calcium silicate and gehlenite. It is thought that those crystalline phase worked as a densification and strengthening mechanism on geopolymer panel surface.