• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.231-234
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• 2001

본 논문은 다단계 상호연결망에서 높은 처리율과 결함 허용을 위해 중복 경로를 제공하는 E-Cube-network 구조를 제안한다. Cube network의 확장된 형태인 E(Extended)-Cube network 구조를 통해 패킷 전송중 충돌이 발생한 경우 스위치 자신을 순환하고, 재차 충돌이 발생하면 멀티플렉서를 통해 또 다른 새로운 경로로 패킷을 전송하는 새로운 알고리즘을 제시한다. 그리고 모의실험을 통해 기존의 Cube network 구조보다 높은 종단간 처리율을 보인다.

• ETRI Journal
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• v.43 no.2
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• pp.344-356
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• 2021

CRAFT is a tweakable block cipher introduced in 2019 that aims to provide strong protection against differential fault analysis. In this paper, we show that CRAFT is vulnerable to side-channel cube attacks. We apply side-channel cube attacks to CRAFT with the Hamming weight leakage assumption. We found that the first half of the secret key can be recovered from the Hamming weight leakage after the first round. Next, using the recovered key bits, we continue our attack to recover the second half of the secret key. We show that the set of equations that are solvable varies depending on the value of the key bits. Our result shows that 99.90% of the key space can be fully recovered within a practical time.

• Advances in concrete construction
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• v.8 no.1
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• pp.1-7
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• 2019

The possibility of using recycled coarse glass aggregates as a substitute for natural crushed stone are relatively limited. In order to promote it for engineering application, this paper reports the effect of coarse glass aggregate on mechanical behavior of concrete. The coarse aggregates are substituted for coarse glass aggregate (CGA) as 0%,20%,40%,60%,80% and 100%.The results show that increasing the coarse glass aggregate content cause decrease in compressive strength, the elastic modulus, the splitting tensile strength, the flexural strength. An equation is presented to generate the relationship between cube compressive strength and prism compressive strength, the relationship between cube compressive strength and elastic modulus, the relationship between cube compressive strength and splitting tensile strength, the relationship between cube compressive strength and flexural strength of coarse glass concrete.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6161-6176
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• 2018

Pseudorandom numbers are useful in cryptographic operations for using as nonce, initial vector, secret key, etc. Security of the cryptosystem relies on the secret key parameters, so a good pseudorandom number is needed. In this paper, we have proposed a new approach for generation of pseudorandom number. This method uses the three dimensional combinational puzzle Rubik Cube for generation of random numbers. The number of possible combinations of the cube approximates to 43 quintillion. The large possible combination of the cube increases the complexity of brute force attack on the generator. The generator uses cryptographic hash function. Chaotic map is being employed for increasing random behavior. The pseudorandom sequence generated can be used for cryptographic applications. The generated sequences are tested for randomness using NIST Statistical Test Suite and other testing methods. The result of the tests and analysis proves that the generated sequences are random.

• Proceedings of the Korea Society of Design Studies Conference
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• 2003.11a
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• pp.94-95
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• 2003

• Journal of KIISE:Databases
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• v.30 no.6
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• pp.553-560
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• 2003

A range-sum query is very popular and becomes important in finding trends and in discovering relationships between attributes in diverse database applications. It sums over the selected cells of an OLAP data cube where target cells are decided by specified query ranges. The direct method to access the data cube itself forces too many cells to be accessed, therefore it incurs severe overheads. The prefix-sum cube was proposed for the efficient processing of range-sum queries in OLAP environments. However, the prefix-sum cube has been criticized due to its space requirement. In this paper, we propose a lossless compression method called the overlapped-subcube that is developed for the purpose of compressing prefix-sum cubes. A distinguished feature of the overlapped-subcube is that searches can be done without decompressing. The overlapped-subcube reduces the space requirement for storing prefix-sum cubes, and improves the query performance.

• Journal of Educational Research in Mathematics
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• v.19 no.3
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• pp.425-441
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• 2009

The cube-accumulation is a new theme included in the 7th elementary mathematics curriculum for improving children's spatial ability. One activity of the cube-accumulation is to recognize the configuration of accumulated cube given three plane figures in the directions of the above, the front and the side, respectively. The approach to this activity presented in the mathematics textbook is more or less intuitive and constructive, and difficult to some children. So we suggest an alternative, more analytic method, 'elimination method', that is eliminating unnecessary parts from $n{\times}n{\times}n$ whole cubes. This method was adopted to the 32 sixth graders, in special five applicants among them. Their responses and activities were analyzed. We confirm that we can teach the cube-accumulation by the elimination method, and some children prefer this method. 13u1 this method requires more exercises to be executed skillfully.

• Archives of design research
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• v.18 no.2 s.60
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• pp.273-282
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• 2005

In this study, we proposed Context Cube as a conceptual model of user context, and a Multi-modal Interaction Design framework to develop ubiquitous service through understanding user context and analyzing correlation between context awareness and multi-modality, which are to help infer the meaning of context and offer services to meet user needs. And we developed a case study to verify Context Cube's validity and proposed interaction design framework to derive personalized ubiquitous service. We could understand context awareness as information properties which consists of basic activity, location of a user and devices(environment), time, and daily schedule of a user. And it enables us to construct three-dimensional conceptual model, Context Cube. Also, we developed ubiquitous interaction design process which encloses multi-modal interaction design by studying the features of user interaction presented on Context Cube.

• Journal of KIISE:Databases
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• v.30 no.3
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• pp.225-236
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• 2003

MOLAP systems store data in a multidimensional away called a 'cube' and access them using way indexes. When a cube is placed into disk, it can be Partitioned into a set of chunks of the same side length. Such a cube storage scheme is called the chunk-based MOLAP cube storage scheme. It gives data clustering effect so that all the dimensions are guaranteed to get a fair chance in terms of the query processing speed. In order to achieve high space utilization, sparse chunks are further compressed. Due to data compression, the relative position of chunks cannot be obtained in constant time without using indexes. In this paper, we propose a bitmap index for chunk-based MOLAP cubes. The index can be constructed along with the corresponding cube generation. The relative position of chunks is retained in the index so that chunk retrieval can be done in constant time. We placed in an index block as many chunks as possible so that the number of index searches is minimized for OLAP operations such as range queries. We showed the proposed index is efficient by comparing it with multidimensional indexes such as UB-tree and grid file in terms of time and space.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.35-42
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• 2005

This paper proposes a new reseeding methodology using a variable-rank multiple-polynomial linear feedback shift register (MP-LFSR). In the proposed reseeding scheme, a test cube with large number of specified bits is encoded with a high-rank polynomial, while a test cube with a small number of specified bits is encoded with a low-rank polynomial. Therefore, according to the number of specified bits in each test cube, the size of the encoded data can be optimally reduced. A variable-rank MP-LFSR can be implemented with a slight modification of a conventional MP-LFSR and Multiple Polynomial can be represented by adding just 1 bit to encoding data. The experimental results on the largest ISCAS'89 benchmark circuits show that the proposed methodology can provide much better encoding efficiency than the previous methods with adequate hardware overhead.