• Applied Chemistry for Engineering
• /
• v.16 no.2
• /
• pp.231-237
• /
• 2005

The sizes and structure of micelles and vesicles formed in ammonium dodecyl sulfate (ADS)/octadecyl trimethyl ammonium chloride (OTAC) mixed aqueous solutions were analyzed by small-angle neutron scattering. In micellar regions of pure ADS and OTAC aqueous solution, the spherical micelles were formed at given concentrations and their sizes were 40 and $61{\AA}$, respectively. The structure transition of pure micelles occurred above 300 mM due to the constancy of the intermicellar distance above 250 mM. The coexisting region of mixed micelles and vesicles in phase diagram of mixed system was also assured. It was investigated that vesicle formed spontaneously took a bilayer structure. The lamellar thickness of vesicles decreased with increasing concentration of vesicle samples. However, the size could not be determined for mixed micelle and vesicle above 100 nm due to limitation of low q ranges. Finally, The 9 mM solution of ADS mole fraction 0.9 (${\alpha}$=0.9) showed bilayer structure compared to phase diagram classified into mixed micelle.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.1
• /
• pp.27-39
• /
• 2008

Landslides cause enormous economic losses and casualties. Korea has mountainous regions and heavy slopes in most parts of the land and has consistently built new roads and large-scale housing complexes according to its industrial and urban growth. As a result, the damage from landslides becomes greater every year. In summer, landslides frequently occur due to local torrential rains and storms. It is critical to predict the potential areas of landslides in advance and to take preventive measures to minimize consequences and to protect property and human life. The previous study on landslides mostly focused on identifying the causes of landslides in the areas where they occurred, and on analyzing landslide vulnerability around the areas without considering rainfall conditions. Thus there were not enough evaluations of the direct risk of landslides to human life. In this study, potentially risky areas for landslides were identified using the GIS data in order to evaluate direct risk on farmlands, roads, and artificial structures that were closely connected to human life. A map of landslide risk was made taking into account rainfall conditions, and a land use map was also drawn with satellite images and digital maps. Both maps were used to identify potentially risky areas for landslides.

• Journal of agriculture & life science
• /
• v.45 no.4
• /
• pp.135-141
• /
• 2011

This research was conducted to provide basic data of surplus heat for designing solar heat-storage systems. The surplus heat is defined as the heat exhausted by forced ventilations from the greenhouses to control the greenhouse temperature within setting limits. Various simulations were performed to compare the differences of thermal behaviors among greenhouse types as well as among several domestic areas by using pseudo-TMY (Typical Meteorological Year) data manipulated based both on the weather data supplied from Korean Meteorological Administration and the TMY data supplied from The Korean Solar Energy Society. Additional analyses were carried out to examine the required heating energy together with some others such as the energy balances in greenhouses to be considered. The results of those researches are summarized as follows. Regional surplus solar heats for the nine regions with 4-type were analyzed. The results showed that the ratio of surplus solar energy compared to heating energy was the highest in Jeju (about 212.0~228.0%) for each greenhouse type. And followed by Busan, Kwangju, Jinju, Daegu, Daejeon, Jeonju, Suwon and Daekwanryung. And irrespective of greenhouse types, surplus solar energy alone could cover up nearly all of the required supplemental heating energy except for a few areas.

• Journal of agriculture & life science
• /
• v.46 no.1
• /
• pp.177-187
• /
• 2012

This study aimed to improve the quality with acomparison of quality characteristics by collecting Chungkukjang in the market, and to establish the foundation data for starter, which support to manufacture standardized Chungkukjang products. Firstly, Chungkukjang was collected from the industrial company and home-made production which located in the several regions of Korea. Moisture contents of collected Chungkukjang were ranged from 56.3 to 62.1% and salinity was 0.23 to 11.51%. Total nitrogen and amino nitrogen contents of Chungkukjang ranged from 5.82 to 8.76% and 173.71 to 2,700.66 mg%, respectively. Nitrogen degradation ratio, which means the proportion of amino nitrogen to total nitrogen, was 2.88~26.93%. Collected Chungkukjang AG and Z have predominant value in histamine and tyramine contents as 755.40 and 1913.51 mg/kg, respectively, and viable cells count in collected Chungkukjang, maximum was $9.6{\times}10^9CFU/g$. As a result, most products showed various properties in flavor and nutrition, and it is supposed to be caused on use of different soybean species and unstandardized fermentation process.

• Journal of the Microelectronics and Packaging Society
• /
• v.26 no.3
• /
• pp.81-88
• /
• 2019

In this study, the effects of graphene oxide (GO) addition on electromigration (EM) lifetime of Sn-3.0Ag-0.5Cu Pb-free solder joint between a ball grid array (BGA) package and printed circuit board (PCB) were investigated. After as-bonded, $(Cu,Ni)_6Sn_5$ intermetallic compound (IMC) was formed at the interface of package side finished with electroplated Ni/Au, while $Cu_6Sn_5$ IMC was formed at the interface of OSP-treated PCB side. Mean time to failure of solder joint without GO solder joint under $130^{\circ}C$ with a current density of $1.0{\times}10^3A/cm^2$ was 189.9 hrs and that with GO was 367.1 hrs. EM open failure was occurred at the interface of PCB side with smaller pad diameter than that of package side due to Cu consumption by electrons flow. Meanwhile, we observed that the added GO was distributed at the interface between $Cu_6Sn_5$ IMC and solder. Therefore, we assumed that EM reliability of solder joint with GO was superior to that of without GO by suppressing the Cu diffusion at current crowding regions.

• Journal of Integrative Natural Science
• /
• v.4 no.1
• /
• pp.38-43
• /
• 2011

The recent global warming may be estimated to give lots of impacts to the human society and biosphere of influencing climate change included by the natural climate variations through the human activity which can directly and/or indirectly play a major role of total atmospheric composition overall. Therefore it currently appears evidences such as hot wave, typhoon, and biosphere disturbance, etc. over the several regions to be influenced by global warming due to increasing the concentration of greenhouse gases in the atmosphere through inducing forest destruction, fossil fuel combustion, greenhouse gases emission, etc. since industrial revolution era. Through the working group report of IPCC (Intergovernmental Panel on Climate Change) for climate change was analyzed by the individual country's current status and figure out the important issues and problems related to the future trend of climate change science with advanced countries preparedness and research, In this study, the first working group report of IPCC focuses on those aspects of the current understanding of the physical science of climate change that are judged to be most relevant to policymakers. As this report was assessed and analyzed by including the progress of climate change science, the role of climate models and evolution in the treatment of uncertainties. This consists of the changes in atmospheric constituents(both aerosols and gases) that affect the radiative energy balance in the atmosphere and determine the Earth's climate, considering the interaction between biogeochemical cycles that affect atmospheric constituents and climate change, including aerosol/cloud interactions, the extensive range of observations snow available for the atmosphere and surface, for snow, ice, and frozen ground and for the oceans, respectively and changes in sea level, the paleoclimate perspective and assessment of evidence for past climate change and the extension, the ways in which physical processes are simulated in climate models and the evaluation of models against observed climate, the development plans and methods of improving expert and building manpower urgently and R&D fund expansion in detail for climate change science in Korea will be proposed.

• Korean Journal of Heritage: History & Science
• /
• v.52 no.1
• /
• pp.82-89
• /
• 2019

In this study observation records of the National Natural Environment Survey (2008-2012, 2014-2017) and the Korean Natural History Research Information System (KNHRIS) for the common kestrel (2013-2016) were consulted to determine the correlation of the distribution of kestrels in an area and the area's land use type. Distribution characteristics were studied based on data collected over the last 10 years (2008-2017). Findings show that the common kestrel is widely distributed between 4,407 sites registered in KNHRIS in the period of 2008-2012, 3,899 sites in 2014-2017, and 508 sites in 2013-2016. Relationship analysis was conducted for the altitude and urban planning factors of statistics based on a 2017 GIS check to determine the distribution characteristics. The birds' altitude was confirmed to range from 0 to 1,200 metersck but was most commonly observed at less than 100 meters. Above 200 meters, the rate of occurrence decreased rapidly. The rate of occurrence of the common kestrel was highest in Chungcheongnam-do province, followed by Gyeongsangbuk-do, Kyonggi-do, Jeollanam-do and Jeollabuk-do. As urban areas, green areas, commercial areas, and industrial areas the presence of swere positively correlated with the presence of kestrels, the rate of occurrence of the kestrel was higher in those regions. However, there was no significant relationship between the incidence of kestrels and housing construction or residential areas.

• Journal of Practical Engineering Education
• /
• v.9 no.1
• /
• pp.69-75
• /
• 2017

In this paper, we analyzed the factors influencing the size of Korea Polytechnic as a public vocational education and training institution through analysis of demand, region, industry, and demand with established existing campus and new campus in Korea Polytechnic. By analyzing data on admission, training, and employment for 3 years out of 37 campuses, we have sampled 5 campuses by type of Korea Polytechnic, fused with the results derived from the literature analysis and in-depth analysis results, so that the regional campus will play a leading role and the direction of development. The selection of five campuses by type is a precedent study to analyze 37 campuses in the future. As a result of the study, the demand analysis through objective indicators such as the number of high school graduates, the number of employed persons, the presence of nearby industrial complexes, and policy variables is very important and reflects the reality well. Therefore, it is necessary to analyze the demand through the objective indicators in decision making related to the new campus at the pre-analysis stage. In addition to the general data proposed in this paper, that is, common variables in all regions, it is important to consider the factors that can reflect local demand characteristics when considering specific locations.

• Journal of Navigation and Port Research
• /
• v.45 no.1
• /
• pp.26-32
• /
• 2021

In ocean field, the spread of the Fourth Industrial Revolution based on information and communication technology requires high precision and stable PNT&D (Position, Navigation, Timing and Data). As the IMO (International Maritime Organization) and IALA (The International Association of Marine Aids to Navigation and Lighthouse Authorities) are requiring backup systems due to mitigate vulnerabilities and the increase of dependency on GNSS (Global Navigation Satellite System), Korea is conducting a research & development of R-Mode. An DGPS (Differentiate Global Positioning System) reference station that uses MF, an existing maritime infrastructure, and AIS (Automatic Identification System) base stations that use 34 integrity station and VHF will be utilized in this study to avoid redundant investment. Because there are radio shadow areas that display low signal levels in the west sea, the establishment of new R-Mode reference and integrity station will be intended to resolve problems regrading the radio shadow area. Because the frequency has a characteristic in that radio wave transmits well along the ground (water surface) in low frequency band, simulation and measurement were conducted therefore this paper to propose candidate sites for R-Mode reference and integrity station resulted through p wave's propagation characteristics analysis. Using this paper, R-Mode reference and integrity station can be established at appropriate locations to resolve radio shadow areas in other regions.

• The Korean Journal of Mycology
• /
• v.48 no.4
• /
• pp.475-484
• /
• 2020

Various indigenous yeasts were isolated and obtained from flowers in the Republic of Korea, and their distribution and species diversity were studied. Seventy-seven flowers were collected from 25 areas in Korea, and 502 yeast strains were isolated from these flowers. A total of 50 species were identified by comparing large subunit rDNA gene sequence homology with the type strains of yeasts. The analysis of yeast distribution showed that the dominant yeast species were Aureobasidium pullulans, A. leucospermi, and Filobasidium magnum in each region and flower samples. Except for the above three yeast species, no species of yeasts showed any meaningful distribution among the habitat regions and sources. In conclusion, 50 species of indigenous yeasts were obtained from flowers that can be used as industrial resources, and the data could be used for further research on yeast diversity and interactions between yeast and its host.