• Title/Summary/Keyword: Data Memory

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Mutual Authentication Mechanism for Secure Group Communications in Sensor Network (센서 네트워크에서의 안전한 그룹통신을 위한 상호 인증 기법)

  • Ko, Hye-Young;Doh, In-Shil;Chae, Ki-Joon
    • The KIPS Transactions:PartC
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    • v.17C no.6
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    • pp.441-450
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    • 2010
  • Recently, a lot of interest is increased in sensor network which gathers various data through many sensor nodes deployed in wired and wireless network environment. However, because of the limitation in memory, computation, and energy of the sensor nodes, security problem is very important issue. In sensor network, not only the security problem, but also computing power should be seriously considered. In this paper, considering these characteristics, we make the sensor network consist of normal sensor nodes and clusterheaders with enough space and computing power, and propose a group key rekeying scheme adopting PCGR(Predistribution and local Collaborationbased Group Rekeying) for secure group communication. In our proposal, we enhance the security by minimizing the risk to safety of the entire network through verifying the new key value from clusterheader by sensor nodes. That is, to update the group keys, clusterheaders confirm sensor nodes through verifying the information from sensor nodes and send the new group keys back to authentic member nodes. The group keys sent back by the clusterheaders are verified again by sensor nodes. Through this mutual authentication, we can check if clusterheaders are compromised or not. Qualnet simulation result shows that our scheme not only guarantees secure group key rekeying but also decreasesstorage and communication overhead.

Neurotoxicity of Synthetic Cannabinoids JWH-081 and JWH-210

  • Cha, Hye Jin;Seong, Yeon-Hee;Song, Min-Ji;Jeong, Ho-Sang;Shin, Jisoon;Yun, Jaesuk;Han, Kyoungmoon;Kim, Young-Hoon;Kang, Hoil;Kim, Hyoung Soo
    • Biomolecules & Therapeutics
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    • v.23 no.6
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    • pp.597-603
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    • 2015
  • Synthetic cannabinoids JWH-018 and JWH-250 in 'herbal incense' also called 'spice' were first introduced in many countries. Numerous synthetic cannabinoids with similar chemical structures emerged simultaneously and suddenly. Currently there are not sufficient data on their adverse effects including neurotoxicity. There are only anecdotal reports that suggest their toxicity. In the present study, we evaluated the neurotoxicity of two synthetic cannabinoids (JWH-081 and JWH-210) through observation of various behavioral changes and analysis of histopathological changes using experimental mice with various doses (0.1, 1, 5 mg/kg). In functional observation battery (FOB) test, animals treated with 5 mg/kg of JWH-081 or JWH-210 showed traction and tremor. Their locomotor activities and rotarod retention time were significantly (p<0.05) decreased. However, no significant change was observed in learning or memory function. In histopathological analysis, neural cells of the animals treated with the high dose (5 mg/kg) of JWH-081 or JWH-210 showed distorted nuclei and nucleus membranes in the core shell of nucleus accumbens, suggesting neurotoxicity. Our results suggest that JWH-081 and JWH-210 may be neurotoxic substances through changing neuronal cell damages, especially in the core shell part of nucleus accumbens. To confirm our findings, further studies are needed in the future.

Implementation of a Sensor Node with Convolutional Channel Coding Capability (컨벌루션 채널코딩 기능의 센서노드 구현)

  • Jin, Young Suk;Moon, Byung Hyun
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.1
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    • pp.13-18
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    • 2014
  • Sensor nodes are used for monitoring and collecting the environmental data via wireless sensor network. The wireless sensor network with various sensor nodes draws attention as a key technology in ubiquitous computing. Sensor nodes has very small memory capacity and limited power resource. Thus, it is essential to have energy efficient strategy for the sensor nodes. Since the sensor nodes are operating on the same frequency bands with ISM frequency bands, the interference by the devices operating on the ISM band degrades the quality of communication integrity. In this paper, the convolutional code is proposed instead of ARQ for the error control for the sensor network. The proposed convolutional code was implemented and the BER performance is measured. For the fixed transmitting powers of -19.2 dBm and -25dBm, the BER with various communication distances are measured. The packet loss rate and the retransmission rate are calculated from the measured BER. It is shown that the porposed method obtained about 9~12% and 12-19% reduction in retransmission rate for -19.2 dBm and -25 dBm respectively.

Tuple Pruning Using Bloom Filter for Packet Classification (패킷 분류를 위한 블룸 필터 이용 튜플 제거 알고리즘)

  • Kim, So-Yeon;Lim, Hye-Sook
    • Journal of KIISE:Information Networking
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    • v.37 no.3
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    • pp.175-186
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    • 2010
  • Due to the emergence of new application programs and the fast growth of Internet users, Internet routers are required to provide the quality of services according to the class of input packets, which is identified by wire-speed packet classification. For a pre-defined rule set, by performing multi-dimensional search using various header fields of an input packet, packet classification determines the highest priority rule matching to the input packet. Efficient packet classification algorithms have been widely studied. Tuple pruning algorithm provides fast classification performance using hash-based search against the candidate tuples that may include matching rules. Bloom filter is an efficient data structure composed of a bit vector which represents the membership information of each element included in a given set. It is used as a pre-filter determining whether a specific input is a member of a set or not. This paper proposes new tuple pruning algorithms using Bloom filters, which effectively remove unnecessary tuples which do not include matching rules. Using the database known to be similar to actual rule sets used in Internet routers, simulation results show that the proposed tuple pruning algorithm provides faster packet classification as well as consumes smaller memory amount compared with the previous tuple pruning algorithm.

Elementary Teachers' Perception, Practice, and Background Factors in Using Students' Everyday Experience in Teaching Science (과학수업에서 학생의 일상경험 도입에 대한 초등교사의 인식과 실행 및 배경요인)

  • Na, Jiyeon;Song, Jinwoong
    • Journal of The Korean Association For Science Education
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    • v.34 no.7
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    • pp.635-645
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    • 2014
  • The purpose of this study is to identify elementary school teachers' perceptions, practices, and background factors related to introducing students' everyday experience in science teaching process. The participants of this study were four elementary school teachers who have different features such as major, teaching period, gender, growth area, and age. The data was collected through semi-constructed and in-depth interviews. The results of the research are as follows: Teachers mostly used students' everyday experience during the introduction phase of science lessons for the purpose of motivation. They hold a positive view of using students' everyday experience during science lessons and thought that science teaching needs to actively use more of students' everyday experience, while in actual practice they disregarded or only passively introduced students' everyday experience. The various background factors found to affect teachers' practice are as follows: positive memory on their science class; educational experience of their own children; their own childhood environment; their learning style; their insufficient knowledge or enthusiasm; perceived educational value of everyday life in science education; teacher's duties; importance of students' achievement; difficulty in guiding experiment; reaction of students on introducing everyday experience; characteristics of science textbook and teacher's guidebook; lack of lesson time; realization of national common basic education; characteristics of their students; demands from parents or students; effect of introducing everyday experience. In addition, we found that the teachers behave not in accordance with what they thought due to external factors related to their profession and that, for a more active use of students' everyday experience in their teaching, teachers need support from textbooks and teachers' guidebooks.

Comparison of Time-Management Ability and ADL between Elderly People Living Alone and Living with Family (독거노인과 가족동거 노인의 시간관리능력과 일상생활활동의 비교)

  • Yoon, Jeong-Ae;Lee, Hyang-Sook;Cha, Jung-Jin;Noh, Jong-Su;Park, Ji-Hoon;Oh, Dong-Hwan
    • The Journal of Korean society of community based occupational therapy
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    • v.3 no.2
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    • pp.1-12
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    • 2013
  • Objective : The objective of this study is to present basic data to find health care plans for the elderly by comparing time-management ability and ADL and identifying the relationships between groups with subjects of elderly people living alone and living with family in Daejeon Metropolitan City. Method : A total of 80 elders who lived alone or with family that were aged 65 or older were selected with MMSE-K, 40 people were selected as subjects for each group. For time-management ability, a questionnaire was used. ADL were assessed by using FIM. The study period was May to June 2013. Result : Comparison of scores for time-management ability and FIM of the elderly who live alone or living with family did not show any statistically significant difference. In comparison of detailed scores between groups, there were statistically significant differences between the two groups being social interaction, problem solving and memory in social cognition items among detailed items. Conclusion : Through this study, we understood that social cognitive function of the aged living alone who had less opportunity of interaction compared to that of the aged living with family was lowered. Based on this, development and study on various programs should be made with consideration of sociodemographic characteristics of the elderly within community-based occupational therapy in the future.

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An Effective Method to Treat The Boundary Pixels for Image Compression with DWT (DWT를 이용한 영상압축을 위한 경계화소의 효과적인 처리방법)

  • 서영호;김종현;김대경;유지상;김동욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.6A
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    • pp.618-627
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    • 2002
  • In processing images using 2 dimensional Discrete Wavelet Transform(2D-DWT), the method to process the pixels around the image boundary may affect the quality of image and the cost to implement in hardware and software. This paper proposed an effective method to treat the boundary pixels, which is apt to implement in hardware and software without losing the quality of the image costly. This method processes the 2-D image as 1-D array so that 2-D DWT is performed by considering the image with the serial-sequential data structure (Serial-Sequential Processing). To show the performance and easiness in implementation of the proposed method, an image compression codec which compresses image and reconstructs it has been implemented and experimented. It included log-scale fried quantizer, but the entropy coder was not implemented. From the experimental results, the proposed method showed the SNR of almost the same SNR(Signal to Noise Ratio) to the Periodic Expansion(PE) method when the compression ratio(excluding entropy coding) of 2:1, 15.3% higher than Symmetric Expansion(SE) method, and 9.3% higher than 0-pixel Padding Expansion(ZPE) method. Also PE method needed 12.99% more memory space than the proposed method. By considering only the compression process, SE and ZPE methods needed additional operations than the proposed one. In hardware implementation, the proposed method in this paper had 5.92% of overall circuit as the control circuit, while SE, PE, and ZPE method has 22%, 21,2%, and 11.9% as the control circuit, respectively. Consequently, the proposed method can be thought more effective in implementing software and hardware without losing any image quality in the usual image processing applications.

A High Speed Block Turbo Code Decoding Algorithm and Hardware Architecture Design (고속 블록 터보 코드 복호 알고리즘 및 하드웨어 구조 설계)

  • 유경철;신형식;정윤호;김근회;김재석
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.7
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    • pp.97-103
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    • 2004
  • In this paper, we propose a high speed block turbo code decoding algorithm and an efficient hardware architecture. The multimedia wireless data communication systems need channel codes which have the high-performance error correcting capabilities. Block turbo codes support variable code rates and packet sizes, and show a high performance due to a soft decision iteration decoding of turbo codes. However, block turbo codes have a long decoding time because of the iteration decoding and a complicated extrinsic information operation. The proposed algorithm using the threshold that represents a channel information reduces the long decoding time. After the threshold is decided by a simulation result, the proposed algorithm eliminates the calculation for the bits which have a good channel information and assigns a high reliability value to the bits. The threshold is decided by the absolute mean and the standard deviation of a LLR(Log Likelihood Ratio) in consideration that the LLR distribution is a gaussian one. Also, the proposed algorithm assigns '1', the highest reliable value, to those bits. The hardware design result using verilog HDL reduces a decoding time about 30% in comparison with conventional algorithm, and includes about 20K logic gate and 32Kbit memory sizes.

Performance Evaluation of the GPU Architecture Executing Parallel Applications (병렬 응용프로그램 실행 시 GPU 구조에 따른 성능 분석)

  • Choi, Hong-Jun;Kim, Cheol-Hong
    • The Journal of the Korea Contents Association
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    • v.12 no.5
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    • pp.10-21
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    • 2012
  • The role of GPU has evolved from graphics-specific processing to general-purpose processing with the development of unified shader core architecture. Especially, execution methods for general-purpose parallel applications using GPU have been researched intensively, since the parallel hardware architecture can be utilized efficiently when the parallel applications are executed. However, current GPU architecture has limitations in executing general-purpose parallel applications, since the GPU is not specialized for general-purpose computing yet. To improve the GPU performance when general-purpose parallel applications are executed, the GPU architecture should be evolved. In this work, we analyze the GPU performance according to the architecture varying the number of cores and clock frequency. Our simulation results show that the GPU performance improves by up to 125.8% and 16.2% as the number of cores increases and the clock frequency increases, respectively. However, note that the improvement of the GPU performance is saturated even though the number of cores increases and the clock frequency increases continuously, since the data cannot be provided to the GPU due to the limit of memory bandwidth. Consequently, to accomplish high performance effectiveness on GPU, computational resources must be more suitably considered.

Dynamic Changes in the Bridging Collaterals of the Basal Ganglia Circuitry Control Stress-Related Behaviors in Mice

  • Lee, Young;Han, Na-Eun;Kim, Wonju;Kim, Jae Gon;Lee, In Bum;Choi, Su Jeong;Chun, Heejung;Seo, Misun;Lee, C. Justin;Koh, Hae-Young;Kim, Joung-Hun;Baik, Ja-Hyun;Bear, Mark F.;Choi, Se-Young;Yoon, Bong-June
    • Molecules and Cells
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    • v.43 no.4
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    • pp.360-372
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    • 2020
  • The basal ganglia network has been implicated in the control of adaptive behavior, possibly by integrating motor learning and motivational processes. Both positive and negative reinforcement appear to shape our behavioral adaptation by modulating the function of the basal ganglia. Here, we examined a transgenic mouse line (G2CT) in which synaptic transmissions onto the medium spiny neurons (MSNs) of the basal ganglia are depressed. We found that the level of collaterals from direct pathway MSNs in the external segment of the globus pallidus (GPe) ('bridging collaterals') was decreased in these mice, and this was accompanied by behavioral inhibition under stress. Furthermore, additional manipulations that could further decrease or restore the level of the bridging collaterals resulted in an increase in behavioral inhibition or active behavior in the G2CT mice, respectively. Collectively, our data indicate that the striatum of the basal ganglia network integrates negative emotions and controls appropriate coping responses in which the bridging collateral connections in the GPe play a critical regulatory role.