• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.163-169
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• 2019

Sn-Pb solder alloys in electronics rapidly has been replaced to Pb free solder alloys because of various environmental regulations such as restriction of hazardous substances directive (RoHS), European Union waste electrical, waste electrical and electronic equipment (WEEE), registration evaluation authorization and of chemicals (REACH) etc. Because Sn58%Bi (in wt.%) solder alloy has low melting point and higher mechanical properties than that of Sn-Pb solder, it has been studied to manufacture electronic components. However, the reliability of Sn58%Bi solder could be lowered because of the brittleness of Bi element included in the solder alloy. Therefore, we observed the microstructures of Sn58%Bi composite solders with various contents of Sn-decorated multiwalled carbon nanotube (Sn-MWCNT) particles and evaluated bonding strength of the FR-4 components assembled with Sn58%Bi composite solder. Also, microstructures and bonding strengths of the Sn58%Bi composite solder joints were evaluated with the number of reflows from 1 to 7 times, respectively. Bonding strengths and fracture energies of the Sn58%Bi composite solder joints were measured by die shear test. Microstructures and fracture modes were observed with scanning electron microscope (SEM). Microstructures in the Sn58%Bi composite solder joints were finer than that of only Sn58%Bi solder joint. Bonding strength and fracture energy of Sn58%Bi composite solder including 0.1 wt.% of Sn-decorated MWCNT particles increased up to 20.4% and 15.4% at 5 times in reflow, respectively.

• The Journal of Korean Academy of Sensory Integration
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• v.16 no.3
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• pp.11-21
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• 2018

Objective : The purpose of this study is to investigate correlation of sensory processing patterns, learning styles and learning strategies for university students. Methods : Participants of this study are 115 students from K university in Busan, South Korea. Measurements are Adolescent/Adult Sensory Profile (AASP) for sensory processing patterns, the Study Process Questionnaire (SPQ) for learning styles, and the Motivated Strategies for Learning Questionnaire (MSLQ) for learning strategies. The data collected was analyzed by SPSS/WIN 20.0 for chisuare test and Pearson corelation coefficient. Results : For sensory processing patterns and learning styles, there were correlation between low registration type and surface type of learning (p=0.03), and between sensory seeking type and deep type of learning (p=0.02). For sensory processing patterns and learning strategies, sensory seeking type was correlated with organized learning strategy (p=0.00), and sensory sensitivity type was correlated with organizational learning strategy (p=0.03) and meta-cognitive learning strategy (p=0.00). Conclusion : This study found that there is correlation between sensory processing patterns, learning styles and learning strategies with implying learning styles and learning strategies can be different depends on sensory procession pattern. The results of this study can be used as a basic data to select learning type and learning strategy appropriate for an individual based on his or her sensory processing patterns.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.485-489
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• 2018

A mungbean cultivar "Munpyeong" (Vigna radiata (L.) Wilczek) was derived as a cross between "Keumseong" and "IT163157" at the Jeollanamdo Agricultural Research and Extension Services (JARES) in 2013. "Munpyeong" has an erect growth habit, heart leaflet, green hypocotyls, black and straight pods when matured, and a dull green seed surface. The stem length of "Munpyeong" was 60 cm, which was 6 cm shorter than that of the control cultivar "Owool." The pod number per plant was 25, which was 3 more than that of the control cultivar. The 1000 seed weight of "Munpyeong" was 45 g, which was 4 g lighter than that of the control cultivar "Owool." Its field resistance to mungbean mottle virus, cercospora leaf spot, and powdery mildew are similar to the control cultivar, whereas its field resistance to lodging was slightly stronger. The hard seed rate of "Munpyeong" was 3.2%, which was similar to that of the control cultivar. The sprout yield ratio was 7.54 times, which was 9% more than that of the control cultivar. The average yield of "Munpyeong" was 1.93 ton/㏊, which was 21% more than that of the control cultivar "Owool" (Cultivar registration number: 5878).

• Korean Journal of Heritage: History & Science
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• v.34
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• pp.222-267
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• 2001

The purpose of this document is to explain the revisions of the Protection of Cultural Properties Act and its sub-laws which have been mad from Jan. 1999 to Sep. 2001. The Protection of Cultural Properties Act and its sub-laws have been revised three times from 1999 to 2001, before and after the Office of Cultural Properties was raised to Cultural Properties Administration on May 24, 1999. The main points of the revisions are as follows. First of all, the role of the local autonomous entities has been increased. The governor of the local autonomous entities is entitled to announce administrative orders related to the preservation of State-designated Cultural Properties. Also, the local autonomous entities has the authorities to examine whether the construction work which will be made in the outer boundaries, which is provided by regulations, of the protected area of the cultural properties might have any effect on preservation of cultural properties or not. Second, preventive actions to protect the cultural properties have been strengthened. If the scale of construction work is more than some scale, the preliminary survey of the surface of the earth to confirm the existence of buried cultural properties and their distribution is obligated. One who is promoting the development plan more than some scale must discuss the plan with the Administrator of Cultural Properties Administration in the process of planning. These actions would be effective to prevent the cultural properties from being damaged because of the development. Third, relaxation of the restrictions has been proceeded. On the basis of regulations which specify the actions to affect the preservation of cultural properties, negative system that does not limit the actions which are not specified in the regulations is introduced. The appropriateness of both protected structure and area should be regularly reviewed and adjusted. Also, most of the restrictions which was made only for administrative convenience and over-regulated the people's living have been revised. Finally, the number of cultural properties to be protected has been increased. Besides the State-designated Cultural Properties, the other cultural properties which are worthy to be protected as City-or-Province-designated Cultural Properties can be designated provisionally and protected. The system of registration and maintenance of the buildings and facilities which are not designated as the Modern Cultural Heritages is established. The penalty for damaging and stealing the cultural Properties which are not designated to be protected was strengthened. Even a dead natural monument can be acknowledged as an natural monument and it is limited to make a specimen or stuffing of the dead natural monument. All of these actions are fit to the high level of understanding of the public about the cultural properties and as the result of these actions, the number of cultural properties to be preserved has been increased. To sum up, the directions of revisions of the Protection of Cultural Properties Act and its sub­laws which have been made from Jan. 1999 to Sep. 2001. are the localization of the protection of the cultural properties, the strengthening of protective actions, the relaxation of various regulations and the increasing of the number fo the protected cultural properties. Also, various problems raised in the processes of implementations of the laws have been reviewed and revised.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.374-381
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• 2022

This case report introduces a 74-year-old male patient who visited retention deficiency of the mandibular implant overdenture, which was fabricated 20 years ago. When the existing dentures were used, the vertical dimension was reduced, the maxillary complete denture lacked lip support and retention, and the mandibular overdenture lacked clip retention due to damage to the bar attachment. After removing the damaged bar attachment, it was replaced with a ball attachment, and impressions were taken using the DENTCA^TM Tray and then the vertical dimension was measured. The gothic arch tracing was performed to record the centric relation. Obtained impressions were scanned and the shape of final dentures was designed using software and try-in dentures were fabricated using 3D printer. After evaluating the occlusal plane, occlusal relationship, facial shape, and pronunciation using the try-in dentures, the bite registration was recorded, and the final denture was manufactured based on this. The inner surface of the denture was adjusted and bilateral balanced occlusion was formed, and the housing was connected to the mandibular denture by a direct method. This case reports have shown satisfactory resultin recovering improved retention and esthetic outcome by increasing the vertical dimension and the lip support using CAD-CAM technique and the ball attachment.

• Korean Journal of Remote Sensing
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• v.32 no.2
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• pp.105-118
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• 2016

The purpose of this study is to improve the classification system of sub-divided land cover map among the land cover maps provided by the Ministry of Environment. To accomplish the purpose, first, the overseas country land cover map classification items were examined in priority. Second, the area ratio of each item established by applying the previous sub-divided classification system was analyzed. Third, the survey on the improvement of classification system targeting the users (experts and general public) who actually used the sub-divided land cover map was carried out. Fourth, a new classification system which improved the previous system by reclassifying 41 classification items into 33 items was finally established. Fifth, the established land cover classification items were applied on study area, and the land cover classification result according to the improvement method was compared with the previous classification system. Ilsan area in Goyang city where there are diverse geographic features with various land surface characteristics such as the urbanization area and agricultural land were distributed evenly were selected as the study area. The basic images used in this study were 0.25 m aerial ortho-photographs captured by the National Geographic Information Institute (NGII), and digital topographic map, detailed stock map plan, land registration map and administrative area map were used as the relevant reference data. As a result of applying the improved classification system into the study area, the area of culture-sports, leisure facilities was $1.84km^2$ which was approximately more than twice larger in comparison to the previous classification system. Other areas such as transportation and communication system and educational administration facilities were not classified. The result of this study has meaningful significance that it reflects the efficiency for the establishment and renewal of sub-divided land cover map in the future and actual users' needs.

• Journal of the Daesoon Academy of Sciences
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• v.27
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• pp.201-243
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• 2016

This paper analyzes the research trends from 358 scholarly articles published in the Journal of Daesoon Academy of Sciences from the first published journal in 1996 to the most recent journal published on the 25^th of 2015 and proposes ideas for improvement. First of all, "The Journal of Daesoon Academy of Sciences" does not meet the standards required by the National Research Foundation, falling short of the most important conditions for the registration such as the periodicity and punctuality expected from academic journals. Furthermore, in terms of the Bibliometrical analysis, the number of articles published by the journal is decreasing and the consistency, with regards to rules and principles regulating publication details and bibliography formats, is nonexistent. Although various authors seemed to be meeting these criteria on the surface, the ratio of co-authored articles is too small. Securing researchers specializing in Daesoon Thought for expanding the size of the journal is important, but it is also important to diversify the research topics through exchanging ideas among researchers from various organizations. Here are some ideas for the improvement of the Journal of Daesoon Academy of Sciences: First, in order to meet the standards for punctuality and periodicity, it would be best to publish the journal twice a year with 12 to 15 articles. Second, the journal must become searchable through the creation of a database. Third, the key words and abstracts of articles must be written in Korean and English to facilitate the sharing of articles among researchers. Fourth, the journal must have a diverse and outstanding editorial board which takes into account the geographical situations of its board members. Fifth, the Journal must include articles on relevant topics that reflect the core topics of the Daesoon Thought and other studies. Sixth, articles must have a front page that contains bibliographical items to convey information to the reader. Seventh, it is essential that the journal have a clear publication date detailing the year, month, and day as well as a standard numbering scheme (i.e, Vol. and no).

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.119-127
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• 2002

This study was conducted to develop the heat exchanger by utilizing the heat energy of underground water(15℃), which might be used for cooling and heating system of the agricultural facilities. We developed the heat exchanger, parallel type plat fin tube made of Aluminum(Al 6063), which was named Aloo-Heat(No. of The registration design : 0247164, by Korean Intellectual property Office). The fin of exchanger was design of the granulated surface for minimizing fouling factor and dew forms, and also placed parallel to the tube in order to minimized the resistance of flows. 1. Aloo-heat was designed to have 0.03m for inside diameter, 0.036m for outside diameter of tube, 0.0012m for thickness of fin and 0.032m for length of plat fin. 2. t was also designed to have 1.5248m²/m for outside area of heat transfer, 0.0942m²/m for inside area contacting hot liquid, and the ratio (Ra) was 16.1869. 3. Efficiency of the fin was 93 percentage when fin length was 0.032m, and the fin thickness satisfied equation $\frac{h{\rho}}{k}$< 0.2 when it was 0.0012m. 4. According to the performance test of Aloo-heat, as the temperature and rate increased, the heating value also increased, heating value was 504kJ/h·m and 6,048kJ/h·m when it was 60℃, 10 𝑙/min and 80℃, 40 𝑙/min respectively. 5. The test of heating value was confident, because correlation value(R²) was 0.9898 for the temperature and 0.9721 for flow rate of hot liquid, respectively.