• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.653-657
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• 2007

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1990 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research's new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean 5.41kWh/$m^2$/day of the direct normal insolation was evaluated for clear day all over 16 areas in Korea. 2) Clear day's direct normal insolation of spring and summer were 5.54kWh/$m^2$/day and 5.86kWh/$m^2$/day, and for fall and winter their values were 5.32kWh/$m^2$/day and 4.92kWh/$m^2$/day respectively. So, spring and summer were higher, and fall and winter were lower than the yearly mean value.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.130.1-130.1
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• 2011

Since the direct normal insolation is a main factor for designing any solar thermal power system, it is necessary to evaluate its characteristics all over the country. We have begun collecting direct normal insolation data since December 1992 at 16 different locations and considerable effort has been made for constructing a standard value from measured data at each station. KIER(Korea Institute of Energy Research)'s new data will be extensively used by solar thermal concentrating system users or designers as well as by research institutes. From the results, we can conclude that 1) Yearly mean $2.67kWh/m^2/day$ of the all day's direct normal insolation was evaluated for all days all over the 16 areas in Korea. 2) All day's direct normal insolation of spring and summer were $2.91kWh/m^2/day$ and $2.23kWh/m^2/day$, and for fall and winter their values were $2.78kWh/m^2/day$ and $2.77kWh/m^2/day$ respectively. So, spring, fall and winter were higher, and summer was lower than the yearly mean value.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4502-4521
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• 2020

At EUROCRYPT 2015, Todo proposed a new technique named division property, and it is a powerful technique to find integral distinguishers. The original division property is also named word-based division property. Later, Todo and Morii once again proposed a new technique named the bit-based division property at FSE 2016 and find more rounds integral distinguisher for SIMON-32. There are two basic approaches currently being adopted in researches under the bit-based division property. One is conventional bit-based division property (CBDP), the other is bit-based division property using three-subset (BDPT). Particularly, BDPT is more powerful than CBDP. In this paper, we use Boolean Satisfiability Problem (SAT)-aided cryptanalysis to search integral distinguishers. We conduct experiments on SIMON-32/-48/-64/-96, SIMON (102)-32/-48/-64, SIMECK-32/-48/-64, LBlock, GIFT and Khudra to prove the efficiency of our method. For SIMON (102)-32/-48/-64, we can determine some bits are odd, while these bits can only be determined as constant in the previous result. For GIFT, more balanced (zero-sum) bits can be found. For LBlock, we can find some other new integral distinguishers. For Khudra, we obtain two 9-round integral distinguishers. For other ciphers, we can find the same integral distinguishers as before.

• Analyses & Alternatives
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• v.6 no.1
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• pp.259-282
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• 2022

This article examines features and implications of 'new northeast phenomenon' in China's new normal period. Different from previous studies with economy as a single factor, this paper regards the northeast phenomenon as not an single economic phenomenon but a compound socio economic phenomenon that economic, demographic and financial issues are linked together. This study finds that since 2014 decline of economic growth, deepening of population decline and brain drain, accelerated aging, the increase in fiscal deficit and a surge in social security spending, these phenomena occur simultaneously and influence each other, forming a vicious cycle in northeast China, and also finds that the difficulty of 'new northeast phenomenon' lies in this compound features. If so, what are the implications of 'new northeast phenomenon's' these features for China as a whole? This study proposes two points. First, based on the recent changes in some relevant situations in China, northeast region can be regarded as a microcosm of China, northeast phenomenon is likely to spread to other regions of China in the near future, it will become a common phenomenon all over China. Second, the emergence of the 'new northeast phenomenon' in the new normal period requires deep reflection and rethinking about the fundamental effect of the regional development strategies, such as 'The Development of the Western Region', 'The Rise of Central China', 'The revitalization of the Northeast', implemented since the reform and development. The 'new northeast phenomenon' has become one of the most urgent problems to be solved by the Chinese government, if the solution is successful, it can be a very useful direction for reconstructing regional development strategies in contemporary China.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12C
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• pp.1297-1308
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• 2006

Multiplications in finite fields are one of the most important arithmetic operations for implementations of elliptic curve cryptographic systems. In this paper, we propose a new multiplication algorithm and VLSI architecture over $GF(2^m)$ using Gaussian normal basis. The proposed algorithm is designed by using a symmetric property of normal elements multiplication and transforming coefficients of normal elements. The proposed multiplication algorithm is applicable to all the five recommended fields $GF(2^m)$ for elliptic curve cryptosystems by NIST and IEEE 1363, where $m\in${163, 233, 283, 409, 571}. A new VLSI architecture based on the proposed multiplication algorithm is faster or requires less hardware resources compared with previously proposed normal basis multipliers over $GF(2^m)$. In addition, we gives an easy method finding a basic multiplication matrix of normal elements.

• Honam Mathematical Journal
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• v.25 no.1
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• pp.141-152
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• 2003

In this paper, we define generalized quasi-preclosed sets and gqp-closed functions and obtain some new characterizations of quasi P-normal spaces and quasi P-regular spaces due to Tapi et al. [9,11]. It is shown that the pairwise continuous pre gqp-closed (resp. pairwise preopen pre gqp-closed) surjective image of quasi P-normal (resp. quasi P-regular) space is quasi P-normal (resp. quasi P-regular).

• Journal of the Korean Mathematical Society
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• v.36 no.4
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• pp.663-677
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• 1999

This work is concerned mainly with the variational problem on an immersion x:M $\rightarrow$} $E^4$ . A new approach is introduced depends on the normal variation in any arbitrary normal direction in the normal bundle. The results of this work are considered as a continuation and an extension to that obtained in [1], [2] and [3], [4] respectively. The methods adapted here are based on Cartan's methods of moving frames and the calculus of variations.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.3
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• pp.280-285
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• 2001

We introduce the new concepts of some fuzzy continuous and closed mappings and study their properties. Also we investigate the properties of fuzzy mildly normal spaces.

• Industrial Engineering and Management Systems
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• v.11 no.2
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• pp.176-182
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• 2012

This paper presents a new approach to risk comparison in uncertain environment. Based on the uncertainty theory, some uncertain risk measures and risk comparison rules are proposed. Afterward the bridges are built between uncertain risk measures and risk comparison rules. Finally, several comparable examples are given.

• Communications of the Korean Mathematical Society
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• v.18 no.3
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• pp.459-468
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• 2003

In this paper, we introduce and study a new class of the generalized set-valued mixed variational inequalities. Using the resolvent operator technique, we construct a new iterative algorithm for solving this class of the generalized set-valued mixed variational inequalities. We prove the existence of solutions for the generalized set-valued mixed variational inequalities and the convergence of the iterative sequences generated by the algorithm.