• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.7
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• pp.817-823
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• 2009

This study was conducted to determine the optimal extraction conditions for maca by comparing the yields, total polyphenol contents, superoxide dismutase (SOD)-like activity and the nitrite scavenging ability. The proximate composition analysis showed 6.57% moisture, 12.83% crude protein, 1.05% crude fat, 4.80% ash and 74.75% carbohydrate. Maca was extracted with 7 different solvents (water, methanol, ethanol, acetone, ethyl acetate, chloroform and hexane) and the extracts were tested for biological activities. The extraction yields of water, methanol and ethanol extracts were 46.2%, 21.4% and 16.8%, respectively. Acetone, ethyl acetate, chloroform and hexane exhibited very low extraction yield, ranging from 0.2 to 1.0%. Total polyphenol contents and the nitrite scavenging ability were the highest in water extract. Electron donating ability and the SOD-like activity were the highest in methanol extract. When water extract was drawn out at different extraction temperatures (30, 70, $100^{\circ}C$) and time (1, 3, 5 hr), the improved biological activities (total polyphenol contents, electron donating ability, SOD-like activity and nitrite scavenging ability) were found in extracts treated at $100^{\circ}C$ for 3 or 5 hrs.

• Food Industry And Nutrition
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• v.14 no.2
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• pp.19-24
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• 2009

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.536-540
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• 2001

본 논문에서는 2개의 직전자를 가지는 선형 MACA부터 유도된 여원CA의 행동에 대한 분석을 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.6
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• pp.1099-1104
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• 2009

Cellular Automata(CA) has been used as modeling and computing paradigm for a long time. While studying the models of systems, it is seen that as the complexity of the physical system increase, the CA based model becomes very complex and becomes to difficult to track analytically. Also such models fail to recognize the presence of inherent hierarchical nature of a physical system. In this paper we analyze the properties of GF($2^p$) multiplue attractor cellular automata(GF($2^p$) MACA) C and give a method of synthesis of C which is a special class of hierarchical cellular automata proposed as an alternative to solve the problem.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.76-89
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• 2014

In this paper, we propose a MAC(Media Access Control) protocol based on flexible RWT(RTS Waiting Time) for underwater mobile ad-hoc networks with a three-way handshaking mechanism. This protocol can solve a problem of collision between RTS(Request-To-Send) and CTS(Clear-To-Send) packets in existing MACA(Multiple Access with Collision Avoidance) protocol. This proposed MAC protocol is also an effective protocol which can apply to underwater mobile ad-hoc networks in a real field by using implementable technologies. We set flexible RTS Waiting Time called RWT, considering various characteristics of underwater environment. It is possible to support variable network size according to node mobility. Finally, we conduct a performance evaluation between proposed MAC protocol and existing MACA based MAC protocol through practical implementation and experiment. As a result, we verify the superiority of our proposed MAC protocol in terms of throughput, packet drop rate, average transmission time, energy consumption and channel utilization.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.673-679
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• 2014

The important requirements of designing a pattern classifier are high throughput and low memory requirements, and low cost hardware implementation. A pattern classifier by using Multiple Attractor Cellular Automata(MACA) proposed by Maji et al. reduced the complexity of the classification algorithm from $O(n^3)$ to O(n) by using Dependency Vector(DV) and Dependency String(DS). In this paper, we generate a pattern classifier using LFSR to improve efficiently the space and time complexity and we propose a method for finding DV by using the 0-basic path. Also we investigate DV and the attractor of the generated pattern classifier. We can divide an n-bit DS by m number of $DV_i$ s and generate various pattern classifiers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.115-118
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• 2014

Underwater Wireless Communication System can be useful for research of quality of water, ocean resources exploration, analysis ocean environment and so on. However, there exist security threats including data loss, data forgery, and another variety of security threats, because of characteristics of water, various geographical factors, intended attack, etc. To solve these problem, in this paper, we propose a CCM-UW mode of operation modified form of CCM mode of operation, providing data confidentiality, integrity, origin authentication and anti-attack prevent, for the Underwater Wireless Communication System. By implementing CCM-UW in MACA protocol(Underwater Wireless Communication MAC Protocol) and measuring speed of communication, we confirm the applicability of the security and analyze the communication environment impact.

• Journal of Korea Multimedia Society
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• v.18 no.11
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• pp.1281-1288
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• 2015

Nongroup Cellular Automata(CA) having two trees in the state transition diagram of a CA is suitable for pattern classifier which divides pattern set into two classes. Maji et al. [1] classified patterns by using multiple attractor cellular automata as a pattern classifier with dependency vector. In this paper we propose a method of generation of a pattern classifier using feature vector which is the extension of dependency vector. In addition, we propose methods for finding nonreachable states in the 0-tree of the state transition diagram of TPMACA corresponding to the given feature vector for the analysis of the state transition behavior of the generated pattern classifier.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.12
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• pp.984-986
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• 2013

DCF(Distributed Coordination Function) defined in IEEE 802.11 provides two different modes, namely, a 2-way handshake and a 4-way handshake according to the transmission procedure. If secondary transmission would not cause a collision with primary transmission, there is no need to postpone transmission unnecessarily. We study a feasible condition which can transmit data concurrently and propose a concurrent transmission scheme.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.97-100
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• 2011

Underwater Wireless Acoustic Sensor Networks have become an important area of research over the recent decades. Designing an underwater network, especially a media access control (MAC) protocol, faces many challenges due to the peculiarities of underwater environment. One of the most important problems is resulted from long and variable propagation delay of the acoustic wave. In this paper, we propose a new method, namely Dynamic Timeout over Multiple Access with Collision Avoidance (DT/MACA), which is designed to handle long and high variable propagation delay in underwater acoustic sensor networks. In this proposed method, the difference timeout intervals are evaluated and applied to each network transmission. Simulation results show that our work not only improves the network throughput, but also decreases the unnecessary retransmission and end-to-end delay.