• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.16 no.2
• /
• pp.25-32
• /
• 2006

In this paper, we propose a fast correlation attack on the shrinking and self-shrinking generator. This attack is an improved algorithm or the fast correlation attack by Zhang et al. at CT-RSA 2005. For the shrinking generator, we recover the initial state of generating LFSR whose length is 61 with $2^{15.43}$ keystream bits, the computational complexity of $2^{56.3314}$ and success probability 99.9%. We also recover the initial state of generating LFSR whose length is $2^{40}$ of the self-shrinking generator with $2^{45.89}$ keystream bits, the computational complexity of $2^{112.424}$ and success probability 99.9%.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.17 no.3
• /
• pp.109-116
• /
• 2007

In this paper, we analyse the security of the variant of Self-Shrinking generator proposed by Chang et al. against a guess-and-determine attack. This variant, which we call SSG-XOR is claimed to have better cryptographic properties than the Self-Shrinking generator in a practical setting. But we show that SSG-XOR is weaker than the Self-Shrinking generator from the viewpoint of guess-and-determine attack.

• KIEE International Transactions on Electrophysics and Applications
• /
• v.3C no.6
• /
• pp.220-223
• /
• 2003

In this paper, a new frequency-to-digital converter without an analog element is proposed. The proposed circuit consists of pulse-shrinking elements, latches and D flip-flops, and the operation is based on frequency comparison by the pulse-shrinking element. In the proposed circuit, the resolution of digital output can be easily improved by increasing the number of the pulse-shrinking elements. The FDC performance is improved in viewpoints of operating speed and chip area. In designed FDC, error of frequency-to-digital conversion is less than 0.1 %.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.1
• /
• pp.87-92
• /
• 1998

Major characteristics of shrinking and rehydration of Korean tea-leaves were investigated in the hot-air drying equipment. Experiments were performed with various drying temperature, plucking time, heating method and rolling condition. The values of shrinking raito and rate were the highest at 7$0^{\circ}C$ in the range of 3$0^{\circ}C$ to 9$0^{\circ}C$. The 1st tea-leaves and showed higher values. Shrinking ratio was 16.62 and 19.62% for leaves and stems; shrinking rate was found 0.083 and 0.091cm/hr.cm, respectively. The rehydration characteristics of tea-leaves at the drying temperature of 3$0^{\circ}C$ were fairly satisfactory. The 2nd tea-leaves showed higher value than others, while the natural tea-leaves were lower. Average rehydration ratio and rehydration rate constant were 85.7% and 0.063/min for leaves; 80.1% and 0.032/min for stems, respectively.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.5 no.4
• /
• pp.418-424
• /
• 2010

Many researchers studied methods for the generation of maximum length pseudo random sequences. Sabater et al. analyzed shrunken sequences which are effectively generated by SG(Shrinking Generator) using CA(Cellular Automata). In this paper we propose a new SG which is called LCSG(LFSR and CA based Shrinking Generator) using an LFSR with control register and CA with generator register. The proposed shrunken sequences generated by LCSG have longer periods and high complexities than the shrunken sequences generated by the known method. And we analyze the generated sequences using LCSG.

• Journal of the Korean Statistical Society
• /
• v.23 no.2
• /
• pp.251-269
• /
• 1994

In this paper we extend Kim and Pollard's cube root asymptotics to other rates of convergence, to establish an asymptotic theory for a multidimensional mode estimator based on uniform kernel with shrinking bandwidths. We obtain rates of convergence depending on shrinking rates of bandwidth and non-normal limit distributions. Optimal decreasing rates of bandwidth are discussed.

• Journal of the Korean Ceramic Society
• /
• v.29 no.1
• /
• pp.15-22
• /
• 1992

The reason for permanent shrinking of recycled castable refractories from alumino-silicate waste refractories was investigated and the method to control shrinking is suggested in order to increase maximum service termperature. The porosity of castable refractories with waste material as large aggregate decreases after heat treatment because the porosity of waste refractories is greater than the of green material, in which CaO around large aggregate penetrates into aggregate and promotes liquid phase sintering. The shrinking of recycled castable refractories resulted in the decrease in porosity can be controled by addition of green kaolin chamotte as large aggregate. The shrinking of recycled castable refractories caused by the differences in densities of mineral phases before and after heat treatment can be controled by addition of kyanite. The use of green kaolin chamotte and kyanite increases the service temperature of recycled castable refractories up to 1500$^{\circ}C$.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.8
• /
• pp.634-641
• /
• 2019

The world's population reached 7.7 billion in 2019. Despite this trend, not all cities are growing. Most of the growing population is driven to large cities for convenience and jobs. This phenomenon has led to a decrease in the population of small and medium-sized cities, and in certain cities, a decrease in employment as well as recession have resulted. Korea is no exception. The nation's population is concentrated in the metropolitan cities. To solve these problems, researchers started to study how to deal with the contraction of a city, i.e., a shrinking city, rather than focusing on only the growth of a city. In this paper, demographically outstanding declined domestic cities were selected as shrinking cities and their characteristics were analyzed. The concept of smart shrinking cities was then defined for the selected cities, which were chosen as a good case in overseas countries to solve the shrinking city problem. Through this process, the strategic differences were compared between domestic and oversea cases. As a result, a modified strategy for the smart shrinking city concept, FSSC (flexible smart shrinking city), is proposed as an alternative strategy that can save resources and cost.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.4
• /
• pp.127-134
• /
• 2019

Recently, the city development policies are being switched to the policies focusing on recession worldwide. Even though South Korea is also facing the phenomena that small and medium-sized cities are downsized because of a decrease in population and an aging society problem, there is lack of solutions and even they are still planning city development policies based on prospect of high growth. This study is featuring 4 viewpoints depending on shrinking population trend in 7 small and medium sized local cities, which are chosen as downsized cities. It is dealing with population peak, current population, 2030 population, and 2040 population viewpoints. And this study uses downsizing simulation that suggests optimum area that fits population and then shows visual check of the status of the small and medium sized local cities. The area of the small and medium sized local cities are expanded more than needs when they are on population peak point. However, they need only 20% to 25% of current area in 2030 and 2040. The most important thing is realizing the seriousness and facing up to the 'shrinking' phenomena that each small and medium-sized cities suffer. Therefore, this study has significance for presenting the status of small and medium-sized cities' problems in South Korea.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.4 no.2
• /
• pp.105-111
• /
• 2001

The shrinking generator is simple and stateable, and known that has good security properties. The bits of one output( $R_1$) are used to determine whether the corresponding bits of the second output will be used as part of the overall keystream. Two LFSRs consisting the generator generate pseudorandom sequences satisfying Golomb's postulates. We used this property to analyze the stream of LFSR $R_1$ of the generator.