• Bulletin of the Korean Chemical Society
• /
• v.12 no.3
• /
• pp.352-354
• /
• 1991

• Bulletin of the Korean Chemical Society
• /
• v.12 no.4
• /
• pp.357-358
• /
• 1991

• Bulletin of the Korean Chemical Society
• /
• v.12 no.4
• /
• pp.360-361
• /
• 1991

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.1 no.1
• /
• pp.91-96
• /
• 1991

The key exchange idea by using a reduced binary indefinite quadratic form has been introdu-ced. This is based on the difficulty of solving the discrete logarithm problem on the class group of a real quadratic field.

• The Journal of the Korea Contents Association
• /
• v.15 no.1
• /
• pp.55-63
• /
• 2015

One of the most notable changes in entertainment programs has been the gamification since 1991. The comparative analysis of 255 weekend entertainment programs run by terrestrial broadcasters between 1991 and 1998 and between 2008 and 2014 indicates that entertainment programs have emigrated from the variety format to the reality, and that adopted entangled plots than interwoven ones more and more, using mission performances and competition heavily. Further, even within the reality format, different competitive factors and plot composition are adding the diversity in the end results immensely. The interaction among the gamification, plots and competitive factors is quite likely to drive creative changes in the broadcast formats in the years to come.

• Journal of radiological science and technology
• /
• v.18 no.1
• /
• pp.81-90
• /
• 1995

This study was conducted to find out the management status of radioisotopes and radioactive waste products in Korean medical institutions during the period of three years from 1991 to 1993. The results are summarized as follows : 1. The rate of medical institution to the institutions making use of radioisotopes was decreased every year, for example, 18.11 % in the year 1991, 17.86 % in the year 1992 and 15.87 % in the year 1993. 2. The use of domestic made radioisotopes in the medical institution was increased every year, for instance, 89.68 % in the year 1991, 94.21 % in the year 1992 and 99.79 % in the year 1993. 3. 91.01 % of the half life of isotopes used in the medical Institution were two month below. 4. The rate of radioactive waste products in the medical institution to all radioactive waste products was increased every year, for example, 54.44 % in the year 1991, 75.36 % in 1992 and 78.49 % in the year 1993. 5. The rate of inflammable waste products from medical institution was 76.47 % of all inflammable waste products, and 73.99 % of whole waste products was from the medical Institution.

• Fire Science and Engineering
• /
• v.23 no.1
• /
• pp.15-20
• /
• 2009

For the effective management of forest fire, understanding of regional forest fire patterns is needed. In this paper, forest fire ignition and spread characteristics were analyzed based on forest fire statistics. Fire occurrences, burned area, rate of spread, and burned area per fire between 1991 and 2007 were parameterized for the cluster analysis, which results were displayed using GIS to detect spatial patterns of forest fire. Administrative districts such as cities and counties were classified into 5 clusters by fire susceptibility. Metropolitan areas had fire characteristics that were infrequent, slow rate of spread, and small burned area. However, 4 cities and counties showing fast rate of spread, and large burned area, in the eastern regions of Taeback Mountain range, were the most susceptible areas to forest fire. The next vulnerable cities and counties were located in the West and South Coast area.

• Journal of Korean Society for Atmospheric Environment
• /
• v.13 no.4
• /
• pp.249-256
• /
• 1997

To identify the long-term influence of acid rain treatment on tree growth, acid rain of various composition (pH 2.0, pH 4.0 and pH 5.6 as control) was applied to several landscape trees for five months (April through August, 1991). Tree height, pH values and $Al^{3+}$ concentration in soil were investigated. Acid rain treatments seemed to promote height growth in the first year (1991), but have become an inhibiting factor over five years. All of coniferous species and most broad-leaved species, except Acer ginnala, showed opposite trends in height responses to acid rain treatments between the first (1991) and last (1996) year. In contrast, Acer ginnala showed similar trends to acid rain treatments in the height growth between 1991 and 1996. This result suggested that Acer ginnala has a characteristic adapability to acid rain stress. pH values of surface soil were lower than those of 30 cm soil depth. This fact suggested that acid rain treatments made surface soil acidic condition. In addition, physiological characteristics (photosynthesis, stomatal condition and biomass) have to be investigated to identify the relationship between long-term effects of $AL^{3+}$ concentration and growth.

• The Korean Journal of Applied Statistics
• /
• v.9 no.1
• /
• pp.31-43
• /
• 1996

The purpose of this study is to reconstruct the Specific Abridged Life Tables of Koreans, based on the Complete Life Tables of the Insurrence Companies of Korea which were constructed by the Korean Actuaries Society in 1988-1991. We compared chronologically the SDRs of the Life Tables by the National STstistica Office and the Specific Abridged Life Tables based on the Empirical Life Tables respectively. And besides, we compared the SDRs of Life Tables by National Statistical Office with the Specific Abrddged Life tabled based on the Empirical Life Tables by the Korean Actuaries Society in 1988-1991. The results of the SDRs of Koresans reveal that the tredns of the Korean Mortality from 1979 to 1991 was on decrease remarkably.

• Journal of Korean Society of Archives and Records Management
• /
• v.18 no.3
• /
• pp.25-47
• /
• 2018

This study aims to analyze the research trends of oral history research in Korea from 1991 to the present, and to provide basic data on the future direction of oral history research. For these purposes, 439 research articles of domestic oral history researchers from 1991 to 2018 were retrieved by keyword search from Research Information Sharing System (RISS) in Korean Education and Research Information Service (KERIS). The research trends of domestic oral history were analyzed by the volume of periodical research papers, major journals, authors and research funds, research fields and research contents, and international cooperation. Finally, based on the results of the study, the implications were summarized, and direction for follow-up research was provided.