• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.5
• /
• pp.1693-1701
• /
• 2010

In this paper, requirements of efficient group key creation in multiple hierarchy structure environment with clear distinction of hierarchical roles within organizations are explained and the method of creating a group key that satisfies such requirements is proposed. The proposed method creates the group key through logical sum operation of hierarchy identifier created using uni-directional hash chain and group identifier randomly created according to the access right. The problem of excessive possession of key information by upper group users in the existing static group key creation technique was resolved. At the same time, lower group users were prevented from deducing key information of upper group users. In addition, as a result of comparative analysis performed with an experiment on existing super group key creation technique and multiple hierarchy group key method, the proposed method was found to be equivalent or superior to existing method in terms of various items including the total number of keys created, the number of keys possessed by users, the number of keys used for encoding and decoding of information, and expandability of keys.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.49 no.5
• /
• pp.79-96
• /
• 2021

Green infrastructure planning represents landscape planning measures to reduce particulate matter. This study aimed to derive factors that may be used in planning green infrastructure for particulate matter reduction using text mining techniques. A range of analyses were carried out by focusing on keywords such as 'particulate matter reduction plan' and 'green infrastructure planning elements'. The analyses included Term Frequency-Inverse Document Frequency (TF-IDF) analysis, centrality analysis, related word analysis, and topic modeling analysis. These analyses were carried out via text mining by collecting information on previous related research, policy reports, and laws. Initially, TF-IDF analysis results were used to classify major keywords relating to particulate matter and green infrastructure into three groups: (1) environmental issues (e.g., particulate matter, environment, carbon, and atmosphere), target spaces (e.g., urban, park, and local green space), and application methods (e.g., analysis, planning, evaluation, development, ecological aspect, policy management, technology, and resilience). Second, the centrality analysis results were found to be similar to those of TF-IDF; it was confirmed that the central connectors to the major keywords were 'Green New Deal' and 'Vacant land'. The results from the analysis of related words verified that planning green infrastructure for particulate matter reduction required planning forests and ventilation corridors. Additionally, moisture must be considered for microclimate control. It was also confirmed that utilizing vacant space, establishing mixed forests, introducing particulate matter reduction technology, and understanding the system may be important for the effective planning of green infrastructure. Topic analysis was used to classify the planning elements of green infrastructure based on ecological, technological, and social functions. The planning elements of ecological function were classified into morphological (e.g., urban forest, green space, wall greening) and functional aspects (e.g., climate control, carbon storage and absorption, provision of habitats, and biodiversity for wildlife). The planning elements of technical function were classified into various themes, including the disaster prevention functions of green infrastructure, buffer effects, stormwater management, water purification, and energy reduction. The planning elements of the social function were classified into themes such as community function, improving the health of users, and scenery improvement. These results suggest that green infrastructure planning for particulate matter reduction requires approaches related to key concepts, such as resilience and sustainability. In particular, there is a need to apply green infrastructure planning elements in order to reduce exposure to particulate matter.

• Korea journal of population studies
• /
• v.19 no.2
• /
• pp.139-173
• /
• 1996

This study is an attempt to identify factors affecting korean immigrants concentration in small business enterprises in the middleman minority sector including the priphery and core sectors, with the private wage and self-employed worker examined in each sector, employing the 5 percent public use sample from the 1980 United States census. One out of five koreans aged 25∼64 years is engaged in self-employed small businesses, while the majority of koreans (4 out of 5) are in the private wage sector. In contrast to expectations, English language difficulties and inferior education are not the prime factors affecting self-employment small businesses. The korean self-employed small business owners both in the periphery sector and in the core sector showed the 'middle' strata of their position in the social structure in terms of their industry, occupation, earnings, etc.

• Korean Journal of Heritage: History & Science
• /
• v.40
• /
• pp.73-104
• /
• 2007

Centering around ruins recognized of being relatively early stage related to flat tile and brick, excavated in Silla capital area, the study attempted elementary approach to seek the appearance time of every remain through comparing them from the excavated cases and production methods of Short beating, Medium beating plate, Long beating plate and Stamped-roof tile. Gyeongju began to use the short beating plate made of tile-less plates or tile plate and increased its quantity. That is deemed to be due to efficiency of beating plate making methods, and moreover to be limited only for use in the palace castle and offices. That is, making short beating plates is presumed to be made merely under some definite objectives. Medium beating plate has been spread to the whole country since Silla and Baekje united. Differently from Koguryo and Baekje, Silla had its unique Beating-plates making technology available for mass-production, which was spread to the whole country and resulted in disappearing of Koguryo and Baekje technology. Long beating plate was not nearly founded in Gyeongju area, but flat tile and common tile excavated in Sachunwang Temple site and Samrang Temple 3rd remains are known. In the outskirts of Gyeongju, long beating plate appeared between the latter half of 8C and the beginning of 9C. Until now, different views have raised to appearance of long beating plate of Unified Silla, which is expected to be clarified under the situation excavated by position relations. Stamped-roof title in Gyeongju is estimated as used after the datum point year 679. While in Baekje area, five stems and branches were involved, in Silla area, code or sign was shown much. The difference between two areas would be due to each other factory, and especially the marked contents werenot letters, which means it had been changed from Baekje s existing-methods. That is, it says the production environment changed owing to Silla's merging. And stamped-roof tile was temporarily used in Gyeongju but soon disappeared, which was because Silla beating plates made under cylinder-shaped tile barrel(圓筒瓦桶) and hitting-pressing of Medium beating plate had beenspread to the whole country, so the production technology of Koguryo and Baekje was naturally dismissed. In consequence, the mergence by Silla brought about unification of each nation's special technology.

• Journal of the Daesoon Academy of Sciences
• /
• v.37
• /
• pp.263-295
• /
• 2021

Until recently, academic consensus held that Zhou Dunyi's Taijitu (Taiji Diagram) originated from Cantongqi. However, a new debate has arisen wherein some scholars question that theory and related theories. They criticize these previous theories because the books and charts used as evidence in those theories were published after the lifetime of Zhou Dunyi, and this disqualifies their influence on his thought. However, identifying certain authors as being of a slightly later period than Zhou Dunyi does not definitively answer whether or not Zhou Dunyi's diagram was based on Cantongqi. I approached this problem from a different perspective. Zhou Dunyi's Taijitu is based on the system of taiji (Taiyi), yin-yang, and the five movements. Consequently, the formation of this system should be traced back historically. In the process of tracing it back, I intended to explain that the main character of Cantongqi is closely related to the formation of the system of taiji (Taiyi), yin-yang, and the five movements. The system of taiji (Taiyi), yin-yang, and the five movements was first established as a religious theological system in the Han Dynasty. In this process, yin-yang and the five movements were combined by Dong Zhongshu, and the five movements were introduced by Han Dynasty scholars as a method of interpreting the I-ching. However, Han Dynasty scholars did not form this system. In the late Han Dynasty, Cantongqi adopted the theological system of yin-yang and the five movements to theoretically form the system of taiji (Taiyi), yin-yang, and the five movements. Cantongqi was able to form this system because of the logic that yin-yang is the essence of the I-ching. Cantongqi does not have the same schematic as Taijitu. However, the system of taiji (Taiyi), yin-yang, and the five movements appears and extracts the components that make up Taijitu. Therefore, I do not think we should hastily agree with the recent claims made by scholars.

• Journal of Nutrition and Health
• /
• v.43 no.5
• /
• pp.533-542
• /
• 2010

The objective of this study is to provide basic information and policy implications needed to balance the supply and demand for dietitian by projecting supply and demand for dietitian. The data from the Ministry of Health Welfare and Family on the number of licensed nutritionist, resident registration data of the Ministry of Public Administration and Security, and health insurance qualification data of the National Health Insurance Corporation were used to examine the current status of supply. To project the supply of nutritionist workforce, the in-out moves method and demographic method were used. The ratios of nutritionist to population and GDP, and that of other countries were applied as the demand projection method. According to the study results, the projection on the imbalance of supply and demand for dietitian by year 2021 differs depending on the method used. First, according to the results based on age-adjusted population ratio, there is an oversupply of 1,643 dietitians in year 2010, and 2,076 dietitians in year 2020. Second, although the projection on the imbalance of the supply and demand for dietitian differs depending on whether the GDD is calculated in won(￦) or dollar($). it is expected that there will be an oversupply in general. Third, as to the scenario using the nutritionist ratio in foreign countries, the oversupply of dietitian is likely in Korea, under any scenario, when comparing the nutritionist supply projection with the demand projection based on the nutritionist ratio in the United States. However, the projection of the supply and demand varies in each scenario when the European nutritionist ratio is applied. Under European 'scenario 1', an oversupply is expected, whereas under 'scenario 2', a shortage of supply is expected. A careful approach is required in interpreting the supply and demand projection using criteria of other countries, because dietitian assumes different roles and functions in each country. Although a slight oversupply of nutritionist workforce is projected, it does not cause a major problem as the demand for diet therapy is expected to rise due to aging and the increase of chronic diseases, and as the demand for clinical dietitians in hospitals increases. Accordingly, the demand for dietitians will rise and, in this context, the oversupply of nutritionist will not incur much problem. However, the nutritionist qualification is much too open in Korea, and this has a negative effect on the quality of the nutritionist workforce. Therefore, it is important that the nutritionist qualifications and requirements are reinforced in the future, enhance the quality level of the nutritionist supply, and maintain the balance between the supply and demand.

• Proceedings of the Korean Sanitation Conference
• /
• 2005.12a
• /
• pp.76-97
• /
• 2005

As the recent change of multiformity and taste in clination in eating habit culture is yearly in creasing foods used oil and fats. Because the frying food is especially important snack , it's safty is very essential. In order to know the safty and harmfulness of frying oil and fats. The 20 kinds samples were purchased chicken fried food shops around the north of seoul and kyunggi. The acid value, iodine value, peroxide value, TBA value, fatty acid, carbonyl value, and smoke point of deep fat fried oils were analyzed. Results of analyzed, A company of deep fat frying oil showed stability state and C company and B company of deep fat frying oil is acidification to turned. But D company of deep fat frying oil showed quite a bit acidification progressived of used hydrogenated oil.

• Korean Journal of Heritage: History & Science
• /
• v.52 no.4
• /
• pp.124-141
• /
• 2019

This research explored the relationship between the water quality issue of Wolji Pond (Anapji Pond) with the maintenance of the channel flow circulation system. The water supply and drainage system closely related to the circulation system of pond has been reviewed, rather than the existing water supply and drainage system that has been analyzed in previous studies. As a result of reviewing the water supply system, it has been learned that the water supply system on the southeastern shore of Wolji Pond, being the current water supply hole, has been connected to the east side garden facility (landscaping stone, curved waterway, storage facility of water) between the north and south fence and the waterway. This separate facility group seems to have been a subject of the investigation of the eastern side of Wolji Pond, with the landscaping stones having been identified in the 1920's survey drawings. The water supply facility on the southeastern shore, being the suspected water supply hole, seems to have some connection with the granite waterway remaining on the building site of Imhaejeon (臨海殿) on the southern side of Wolji Pond. It is inferred that it provides clean water, seeing that the slope towards the southwestern shore of Wolji Pond becomes lower, the landscaping stones have been placed in the filter area, and it is present in the 1920's survey drawings and the water supply hole survey drawing of 1975. The water drainage facility on the northern shore is composed of five stages. The functions of the wooden waterway and the rectangular stone water catchment facility seem not to be only for the water drainage of Wolji Pond. In light of the points that there are wood plugs in the wooden waterway and that there is a water catchment facility in the final stage, it is judged that the water of Balcheon Stream (撥川) may be charged in reverse according to this setup. Namely, the water could enter and exit in either direction in the water drainage facility on the northern shore It also seems that the supply to the wooden waterway could be opened and shut through the water catchment facility of rectangular stone group as well. The water drainage facility on the western shore is very similar to the water drainage facility on the northern shore, so it is difficult to avoid the belief that it existed during the Silla Dynasty, or it has been produced by imitating the water drainage facility on the northern shore at some future point in time. It seems to have functioned as the water drainage facility for the supply of agricultural water during the Joseon Dynasty. The water supply and drainage facilities in Wolji Pond have been understood as a systematized distribution network that has been intertwined organically with the facility of Donggung Palace, which was the center of the Silla capital. Water has been supplied to each facility group, including Wolji Pond, through this structure; it includes the drainage system connecting to the Namcheon River (南川) through the Balcheon Stream, which was an important canal of the capital center.