• ETRI Journal
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• v.43 no.4
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• pp.640-649
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• 2021

In this paper, an additional degree of freedom in phased multi-input multi-output (phased-MIMO) radar with any arbitrary desired covariance matrix is proposed using space-time codes. By using the proposed method, any desired transmit covariance matrix in MIMO radar (phased-MIMO radars) can be realized by employing fully correlated base waveforms such as phased-array radars and simply extending them to different time slots with predesigned phases and amplitudes. In the proposed method, the transmit covariance matrix depends on the base waveform and space-time codes. For simplicity, a base waveform can be selected arbitrarily (ie, all base waveforms can be fully correlated, similar to phased-array radars). Therefore, any desired covariance matrix can be achieved by using a very simple phased-array structure and space-time code in the transmitter. The main advantage of the proposed scheme is that it does not require diverse uncorrelated waveforms. This considerably reduces transmitter hardware and software complexity and cost. One the receiver side, multiple signals can be analyzed jointly in the time and space domains to improve the signal-to-interference-plus-noise ratio.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.298-310
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• 2021

Prediction of the behavior of heavy metals over time is important to evaluate the heavy metal toxicity in algae species. Various modeling studies have been well established, but there is a need for an improved model for predicting the chronic effects of metals on algae species to combine the metal kinetics and biological response of algal cells. In this study, a kinetic dynamics model was developed to predict the copper behavior(5 ㎍ L^-1, 10 ㎍ L^-1, and 15 ㎍ L^-1) for two freshwater algae (Pseudokirchneriella subcapitata and Chlorella vulgaris) in the chronic exposure experiments (8 d and 21 d). In the experimental observations, the rapid change in copper mass between the solutions, extracellular and intracellular sites occurred within initial exposure periods, and then it was slower although the algal density changed with time. Our model showed a good agreement with the measured copper mass in each part for all tested conditions with an elapsed time (R² for P. subcapitata: 0.928, R² for C. vulgaris: 0.943). This study provides a novel kinetic dynamics model that is compromised between practical simplicity and realistic complexity, and it can be used to investigate the chronic effects of heavy metals on the algal population.

• International Journal of Computer Science & Network Security
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• v.24 no.9
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• pp.41-49
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• 2024

This paper proposes dual symbol superposition block carrier transmission with frequency domain equalization (DSS-FDE) system. This system is based upon χ-transform matrix, which is obtained by concatenation of discrete Hartley transform (DHT) matrix and discrete Fourier transform (DFT) matrices into single matrix that is remarkably sparse, so that, as it will be shown in this paper, it only has non-zero entries on its principal diagonal and one below the principle anti-diagonal, giving it shape of Latin alphabet χ. When multiplied with constellation mapped complex transmit vector, each entry of resultant vector is weighted superposition of only two entries of original vector, as opposed to all entries in conventional DFT based OFDM. Such a transmitter is close to single carrier block transmission with frequency domain equalization (SC-FDE), which is known to have no superposition. The DSS-FDE offers remarkable simplicity in transmitter design and yields great benefits in reduced complexity and low PAPR. At receiver-end, it offers the ability to harvest full diversity from multipath fading channel, full coding gain, with significant bit error rate (BER) improvement. These results will be demonstrated using both analytical expressions, as well as simulation results. As will be seen, this paper is Part III of three-paper series on alternative transforms for multicarrier communication (MC) systems.

• Journal of the Korean Dietetic Association
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• v.5 no.2
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• pp.194-204
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• 1999

The objectives of this study were to assess the current practices of implementing selective menus and to identify the perception of foodservice manager and customer on selective menus for hospital foodservice would be fulfilled. Two types of questionnaires for hospital foodservice managers as well as customers were developed. Questionnaires were distributed to managers of 8 hospital foodservice department and 317 customers of patient meal service, and 6 managers and 139 customers were responded. The data were analyzed using frequency and t-test. The results of this study can be summarized as follows : 1. In hospital foodservice operations, the selective menu pattern was first introduced by L hospital on June 1994 in Seoul and recently 8 hospitals were currently implementing selective menus. But using rate of selective menus by patients were relatively low(23.2%), ranging from 15% to 32%. 2. Customers' needs for selective menus were rated significantly higher in the group of patients(4.24/5) who chose the selective menus than their counterpart(3.88/5). 3. The main reason not choosing selective menus was identified by patients as 'not knowing the implementation of selective menus'(52.6%), inconvenient factors in using selective menus for customer were also identified as orders : 'lack of nutrition information on menu item'(38.6%), 'complexity in procedure'(29.8%), and 'lack of menu variety'(26.3%). However managers considered 'managerial burden' and 'limited human resource' as main obstacle to implement the selective menu pattern. 4. Customers indicated 'variety of menu', 'active public relations' as effective methods to enhance using rate of selective menus, however, foodservice manager indicated 'variety of menu'(50%), 'improvement of quality'(16.7%), and 'simplicity in procedure'(16.7%). Based on the results of this study, following recommendations have been suggested : Managers in patient meal service should recognize customer needs for implementing selective menus and pay more attention in implementing selective menus and activating this program. For more effective implementation of activating selective menu program, the foodservice department should establish action plan on 'active publicity work', 'simplicity in procedures', 'variety of menu' and 'improvement of quality'. Especially nutrition informations on meals should be provided for customers in order to elevate participation rate.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.105-111
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• 2024

This paper deals with the minimum linear arrangement(MinLA) of a lattice graph, to which an approximate algorithm of linear complexity O(n) remains as a viable solution, deriving the optimal MinLA of 31,680 for 33×33 lattice. This paper proposes a partitioning arrangement algorithm of complexity O(1) that delivers exact solution to the minimum linear arrangement. The proposed partitioning arrangement algorithm could be seen as loading boxes into a container. It firstly partitions m rows into r₁,r₂,r₃ and n columns into c₁,c₂,c₃, only to obtain 7 containers. Containers are partitioning with a rule. It finally assigns numbers to vertices in each of the partitioned boxes location-wise so as to obtain the MinLA. Given m,n≥11, the size of boxes C₂,C₄,C₆ is increased by 2 until an increase in the MinLA is detected. This process repeats itself 4 times at maximum given m,n≤100. When tested to lattice in the range of 2≤n≤100, the proposed algorithm has proved its universal applicability to lattices of both m=n and m≠n. It has also obtained optimal results for 33×33 and 100×100 lattices superior to those obtained by existing algorithms. The minimum linear arrangement algorithm proposed in this paper, with its simplicity and outstanding performance, could therefore be also applied to the field of Very Large Scale Integration circuit where m,n are infinitely large.

• Korean Institute of Interior Design Journal
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• v.22 no.6
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• pp.151-161
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• 2013

This study which analyzed 4th century Constantinus basilica church architecture is on how the Roman basilica architecture became to christianized and christian architecture became romanized. Basilica architecture of Rome which has strong public characteristic had approach from various direction, especially it has formed inter communicable open space to center forum. Even though, the early christian church has became to bigger size on the process of domus ecclesia centered growth, but it has formed essencially unhierarchy community of home based, it also seemed to have loose religious community below hundred. The result of analyzing 22 of 4 century basilica churches had been shown that more than 60% of them were built on historical place such as tomb of martyr, nearly 70% of them were long axis type, the size of church showed up $3,200m^2$ of average total area. In conclusion, this study concluded the result of christianized showed closeness pursue holiness by separation from the secular world, and long axis it was revealed as mass for the procession ceremony of catholic church. The result of romanized occurred from the process that the basilica church abandoned the unhierarchy, small sizing, worship simplicity of early domus ecclesia characteristics and accept hierarchy, big sizing, worship formalism and complexity of Roman empire system in the roman basilica churches. Through this study it could be grasp that the romanized of early christianity bring not only the change of church architecture but also degeneration of christian itself.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.42-53
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• 2000

Efficient implementation of pre-filtering has been an important issue in video sequence coding, because it can remove camera noise and improve coding efficiency dramatically This paper introduces a novel pre-filtering scheme that is performed inside a video encoder The proposed pre-filtering is based on the approximated generalized Wiener filtering and two-dimensional discrete cosine transform (DCT) factorization. and is achieved by scaling the DCT coefficients of original image blocks for intra block coding and those of motion-compensated error blocks for inter block coding, respectively Even though the pre-filtering operation is embedded in a video encoder, its additional computational complexity is marginal compared to the encoding process, and the overall architecture of the conventional video encoder is maintained In spite of its simplicity, the proposed pre-filtering scheme provides good filtering and coding performance for noisy video sequences.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.1
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• pp.50-58
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• 2003

Among finite field arithmetic operations, the $AB^2$ operation is known as an efficient basic operation for public key cryptosystems over $GF(2^m)$,Division/Inversion is computed by performing the repetitive AB$^2$ multiplication. This paper presents two new $AB^2$algorithms and their systolic realizations in finite fields $GF(2^m)$.The proposed algorithms are based on the MSB-first scheme using standard basis representation and the proposed systolic architectures for $AB^2$ multiplication have a low hardware complexity and small latency compared to the conventional approaches. Additionally, since the proposed architectures incorporate simplicity, regularity, modularity, and pipelinability, they are well suited to VLSI implementation and can be easily applied to inversion architecture. Furthermore, these architectures will be utilized for the basic architecture of crypto-processor.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.127-135
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• 2018

Men are ambivalent since they have good and evil at the same time. To concretize this evil further, men created symbolic icons of evil with formative elements by giving shape to it. Thus, this researcher would investigate and analyze the concept of evil and the formativeness appearing when the essence of humans' evil is expressed as symbolic icons. For this purpose, items for the classification of formativeness were constructed, and questionnaires were prepared to draw the results of an analysis as follows. As for the type of composition, symbolic icons of evil were expressed by pictures or signs, rather than letters. The objects of expression were characters and animals in myths. As for the layout, most were expressed in a radial shape. As for the method of description, most were in the forms of simplicity and complexity, and as for the outer form, most were circles. It was noted that the symbolic icons in which items with these types of composition had high scores, were drawn, used and developed in formative relations with each other.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.720-725
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• 2013

Nylon wire cutting method by nichrome wire is generally applicable for cube satellite applications due to its advantages of simplicity. However, the system complexity is not avoidable to apply it on the cube satellite with multi-deployable structures. A lower constraint force of the mechanism is also one of the disadvantages of the mechanism. In this study, we proposed a preliminary structure design of cube satellite with the separation mechanism which is applicable for holding and release of the multi-deployable structures. The effectiveness of the mechanism design was verified through function test of EM mechanism. The structure analysis results showed that the structure design proposed in this study is feasible.