• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1611-1633
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• 2022

At EUROCRYPT 2019, a new block cipher algorithm called BISON was proposed by Canteaut et al. which uses a novel structure named as Whitened Swap-Or-Not (WSN). Unlike the traditional wide trail strategy, the differential and linear properties of this algorithm can be easily determined. However, the encryption speed of the BISON algorithm is quite low due to a large number of iterative rounds needed to ensure certain security margins. Commonly, denoting by n is the data block length, this design requires 3n encryption rounds. Moreover, the block size n of BISON is always odd, which is not convenient for operations performed on a byte level. In order to overcome these issues, we propose a new block cipher, named DBISON, which more efficiently employs the ideas of double layers typical to the BISON-like construction. More precisely, DBISON divides the input into two parts of size n/2 bits and performs the round computations in parallel, which leads to an increased encryption speed. In particular, the data block length n of DBISON can be even, which gives certain additional implementation benefits over BISON. Furthermore, the resistance of DBISON against differential and linear attacks is also investigated. It is shown the maximal differential probability (MDP) is 1/2^n-1 for n encryption rounds and that the maximal linear probability (MLP) is strictly less than 1/2^n-1 when (n/2+3) iterative encryption rounds are used. These estimates are very close to the ideal values when n is close to 256.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.131-140
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• 2018

A broadcast scheduling scheme is an essential technique to improve the performance of data broadcast systems. This paper explores the problem of data broadcast over multiple channels to reduce query response time, and proposes a new hybrid data broadcast scheduling scheme named HDAMA. The proposed scheme employs the strategy that combines the advantages of push-based broadcast and pull-based broadcast. HDAMA could enhance the performance of query response time since it is capable of controlling the influence of access probability properly reflecting the characteristics of multi-data queries and broadcasting pull data items relatively on time. Simulation is performed to evaluate the performance of the proposed scheme. The simulation results show that the performance of HDAMA is superior to other schemes in terms of the average response time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.53-56
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• 2008

Recently, the distributed system is being evolved into a new paradigm, named cloud computing, which provides users with efficient computing resources and services from data centers. Cloud computing would reduce the potential danger of Grid computing which utilizes resource sharing by constructing centralized data center. In this paper, a new data replication scheme is proposed for Hadoop distributed file system by changing 1:1 data transmission to 1:N. The proposed scheme considerably reduced the data transmission delay comparing to the current mechanism.

• Atmosphere
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• v.18 no.4
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• pp.287-297
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• 2008

The vertical profiles and optical properties of Asian dust are investigated using ground-based measurements from 1998 to 2002. Vertical profiles of aerosol extinction coefficient are evaluated using MPL (Micro Pulse Lidar) data. Optical parameters such as aerosol optical thickness ($\tau$), ${\AA}ngstr\ddot{o}m$ exponent ($\alpha$), single scattering albedo ($\omega$), refractive index, and volume size distribution are analyzed with sun/sky radiometer data for the same period. We can separate aerosol vertical profiles into three categories. First category named as 'Asian dust case', which aerosol extinction coefficient is larger than $0.15km^{-1}$ and dust layer exists from surface up to 3-4km. Second category named as 'Elevated aerosol case', which aerosol layer exists between 2 and 6km with 1-2.5km thickness, and extinction coefficient is smaller than $0.15km^{-1}$. Third category named as 'Clear sky case', which aerosol extinction coefficient appears smaller than $0.15km^{-1}$. and shows that diurnal variation of background aerosol in urban area. While optical parameters for first category indicate that $\tau$ and $\alpha$ are $0.63{\pm}0.14$, $0.48{\pm}0.19$, respectively. Also, aerosol volume concentration is increased for range of 1 and $4{\mu}m$, in coarse mode. Optical parameters for second category can be separated into two different types. Optical properties of first type are very close to Asian dust cases. Also, dust reports of source region and backward trajectory analyses assure that these type is much related with Asian dust event. However, optical properties of the other type are similar to those of urban aerosol. For clear sky case, $\tau$ is relatively smaller and $\alpha$ is larger compare with other cases. Each case shows distinct characteristics in aerosol optical parameters.

• Journal of the Korea Society of Computer and Information
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• v.26 no.2
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• pp.99-108
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• 2021

This is a study on the type of perception about the transition of female firefighters to emergency car drivers. The purpose of this study is to identify the perception of the female firefighters on the circulation of emergency car drivers and to identify the characteristics of each type of firefighting officers and to provide basic data for the development and utilization of the emergency car drivers' work of female firefighters. The Q-sample of 27 statements was conducted on 31 subjects including 26 women and 5 men, and the data were analyzed using the QUANL program. As a result, the three types classified explained 60.8 % of the total variance, and the explanation power of each type was 50 % for type I, 5.6 % for type II, and 5.2% for type III. Type I was named 'feminist type', type II was named 'future-oriented type', and type III was named 'educational preparation type'. According to the perception of emergency cars by female firefighters, it was investigated that discrimination caused by gender should be eliminated and female firefighters can drive an emergency car if preparation and systematic education are made. Therefore, fire officials need to develop their personal abilities through gender equality and systematic education programs.

• Korean Journal of Computational Design and Engineering
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• v.21 no.1
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• pp.51-60
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• 2016

The arrangement design of a submarine has been performed based on data of parent ships and experts' experiences. To support such a task, it is necessary to accumulate and use systematically the data, and to optimize the task. The expert system for the first issue and the optimization method for the latter issue can be used. At this time, a suitable data structure to share the data on the arrangement design of the submarine should be used. In this study, the data structure named an arrangement template model (ATM) is proposed. To check the applicability of the ATM, a prototype program which consists of the expert system and the optimization method is developed. Finally, the developed program is applied to a small submarine of US Navy. As a result, it is confirmed that the ATM can be used to share the data between the expert system and the optimization method.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.4
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• pp.165-179
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• 2019

This study used 3D body scan data to classify body shapes according to the torso shape of adult males aged 20-75 years. This data will be provided so that the apparel industry can make apparel products corresponding to body characteristics by age. The study used 1,796 adult males between the ages of 20 and 75 and the 3D body shape data of the '5th Research on National Standard Anthropometry'. For data analysis, the program SPSSWIN Ver. 17.0 was used to calculate the mean and frequency allowing for a factor analysis, cluster analysis, analysis of variance, and Duncan test. To classify body shape according to the torso shape of adult males, this study considered nine factors: 'horizontal size of torso,' 'vertical size of body,' 'curve of torso and waist-abdomen flatness ratio,' 'length of torso,' 'shape of neck area,' 'degree of lateral curve,' 'difference between front and back interscye length,' 'shoulder armscye shape,' and 'chest flatness ratio.' Based on the results of the factor analysis, the torso shapes of adult males were classified into five types. Type 1 is "upright body with flat, curvy shape", Type 2 is "curve sway back body type", Type 3 is "flat, abdominally obese body", Type 4 is "obese, crooked body" and Type 5 is "thick sway front body type." named.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.59-64
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• 2003

This study was carried out to develop database system using internet fur greenhouse. The database system consisted of group monitor, client monitor. server monitor and DBMS. The results of the study are summarized as follows. 1. The monitoring module, as data collection system for database. could monitor the state of the control device and the greenhouse environment. 2 The group monitor was connected to the house monitors by RS-485 communication method. Data received by the group monitor were sent to the server monitor and then stored in database server by TCP/IP and MIDAS. 3. The data of database consisted of on growing environment. control devices, operation and cultivation data in greenhouse. It was developed using MS-SQL server. 4. Remote monitoring of greenhouse was realized in a client/server environment. The client module. which was named as the client monitor. made requests to access the measurement data of greenhouse through the remote data module of the server monitor in internet environment.

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.961-970
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• 2003

In data broadcasting environments, the server periodically broadcasts data items in the broadcast channel. When each client wants to access any data item, it should monitor the broadcast channel and wait for the desired item to arrive. Client data caching is a very effective technique for reducing the time spent waiting for the desired item to be broadcastted. This paper proposes a new client cache management scheme, named LRU-CFP, to reduce this waiting time ans evaluates its performance on the basis of a simulation model. The performance results indicate that LRU-CFP scheme shows superior performance over LRU, GRAY and CF in the average response time.

• The Journal of Information Technology
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• v.7 no.1
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• pp.57-67
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• 2004

Data broadcast has attracted a lot of attention as an efficient way of disseminating data to very large client populations. The main motivation of data broadcast systems is that the number of clients that they serve can grow arbitrarily large without any effect on their performance. The performance of broadcast system depends mainly on client caching strategies and on data broadcast scheduling mechanisms. This paper addresses the latter issue and proposes a new broadcast scheduling scheme, named RxW$^{\alpha}$, that is suitable to data broadcast systems. This paper also evaluates the performance of RxW$^{\alpha}$ on the basis of a simulation model. The performance results indicate that RxW$^{\alpha}$ is capable of improving the performance in the variance of response time significantly, showing a reasonable performance in the response time.