• Journal of IKEEE
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• v.16 no.3
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• pp.274-282
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• 2012

In this paper, we propose the design of lighting control algorithm for intelligent LED lighting system. The proposed lighting control algorithm transmitted to MCU through a data bus the environmental information detected from respectively sensor node. The MCU control software was designed to determine the level maintained to depending on the set control method by comparing the results that calculated the dimming level using a signal value. Also, it was designed to be lighting by cross-performed periodically the rotation and reverse method by created fully symmetrical pattern using the control algorithm to LED lighting device. In this paper, the proposed lighting control algorithm improved the reliability of the data sent by designed the system that can be controlled lighting to stable, and it was maintained the event delivery ratio of 91%. Also, the lighting device was decreased the luminous intensity of 32%, the power consumption of 49%, and heat generation of 32%. As a result, it were could be improved the energy efficiency that the life-cycle of LED has been increased 50%.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.3
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• pp.29-38
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• 2006

Recent advances in wireless communication technology promotes many researches related to sensor network and brings several proposals to fit into various types of sensor network communication. The research direction for sensor network is divided into the method to maximize an energy efficiency and security researches that has not been remarkable so far. To maximize an energy efficiency, the methods to support data aggregation and cluster-head selection algorithm are proposed. To strengthen the security, the methods to support encryption techniques and manage a secret key that is applicable to sensor network are proposed, In. However, the combined method to satisfy both energy efficiency and security is in the shell. This paper is devoted to design the protocol that combines an efficient clustering protocol with key management algorithm that is fit into various types of sensor network communication. This protocol may be applied to sensor network systems that deal with sensitive data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.1B
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• pp.11-16
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• 2007

This paper describes the design and performance of a secure routing protocol with time-space cryptography for mobile ad-hoc networks. The proposed time-space scheme works in the time domain for key distribution between source and destination as well as in the space domain for intrusion detection along the route between them. For data authentication, it relies on the symmetric key cryptography due to high efficiency and a secret key is distributed using a time difference from the source to the destination. Also, a one-way hash chain is formed on a hop-by-hop basis to prevent a compromised node or an intruder from manipulating the routing information. In order to evaluate the performance of our routing protocol, we compare it with the existing AODV protocol by simulation under the same conditions. The proposed protocol has been validated using the ns-2 network simulator with wireless and mobility extensions.

• Convergence Security Journal
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• v.16 no.5
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• pp.3-9
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• 2016

The wireless sensor networks have become an economically viable monitoring solution for a wide variety of civilian and military applications. The main challenge in wireless sensor networks is the secure transmission of information through the network, which ensures that the network is secure, energy-efficient and able to identify and prevent intrusions in a hostile or unattended environment. In that correspondence, this paper proposes a distributed clustering process that integrates the necessary measures for secure wireless sensors to ensure integrity, authenticity and confidentiality of the aggregated data. We use the notion of pre-distribution of symmetric and asymmetric keys for a secured key management scheme, and then describe the detailed scheme which each sensor node within its cluster makes use of the pre-distribution of cryptographic parameters before deployment. Finally, we present simulation results for the proposed scheme in wireless sensor network.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.247-255
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• 2011

Most existing clustering protocols have been aimed to provide balancing the residual energy of each node and maximizing life-time of wireless sensor networks. In this paper, we present the adaptive clustering strategy related to sink position for clustering protocols in wireless sensor networks. This protocol allows networks topology to be adaptive to the change of the sink position by using symmetrical clustering strategy that restricts the growth of clusters based on depth of the tree. In addition, it also guarantees each cluster the equal life-time, which may be extended compared with the existing clustering protocols. We evaluated the performance of our clustering scheme comparing to LEACH and EEUC, and observe that our protocol is observed to outperform existing protocols in terms of energy consumption and longevity of the network.

• The KIPS Transactions:PartC
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• v.14C no.6
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• pp.493-502
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• 2007

In this paper, we propose a handoff-aware DiffServ scheduler which intends to guarantee various QoS requirements of multimedia services for mobile nodes in TDD/CDMA based wireless networks. TDD is widely used duplexing mechanism in wireless communications. Unlike FDD, TDD allows a node to symmetrically communicate with a base station by using a single frequency band, resulting in high utilization of wireless resources. DiffServ is regarded as a relatively simple QoS support mechanism and thus it is easy to be extended. This is because DiffServ is not a per-flow based mechanisms and it does not require any signaling protocol. However, previously proposed DiffServ schedulers for wired networks can not be deployed directly into wireless networks since they do not consider properties of wireless networks. As a solution to the problem, DSS(DiffServ Supporting Scheduler) was proposed. DSS uses uplink channel, which is originally used for a node to require a base station to transmit packets, to support QoS efficiently. However, QoS does not consider handoff so that it can not support QoS for moving nodes from one cell to the other cell. Therefor. the proposed handoff support QoS mechanism is necessary for TCC/CDMA networks. The proposed scheme allows a mobile node to achieve seamless service without QoS degradation even for the handoff duration.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.85-88
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• 1994

근래 골조직에 있어서 자율신경의 기능에 대하여 많은 연구가 이루어지고 있으며, 골내의 자율신경의 해부학적 분포는 많이 알려져 있다. 그러나 임상적으로 반사적 교감신경 이상이나 레이노드 현상등과 같은 교감신경의 기능이상증에서나, 버거씨병 등의 치료 목적으로 시행되고 있는 교감신경 절제술 후, 자율신경기능의 변화가 사지골의 혈류나 골대사에 미치는 영향에 대하여는 아직도 논란의 여지가 있다. 저자들은 교감신경절제술 후 시간 경과에 따른 골에 미치는 영향을 알아보기 위하여 흰쥐에서 골대사와 혈류상태를 비교적 충실히 반영하는 정량적 골스캔을 시행하였다. 체중 $300{\sim}400g$의 수컷 흰쥐 10마리에서 복강을 통한 편측 요추부 교감신경절제술을 시행하였고, 수술 전과 후 1일, 3일, 1주, 2주, 3주, 4주에 양측 하지에서 각각 골스캔을 시행하고 교감신경 절제측 하지와 정상 하지에 대칭적으로 관심구역을 정하여 양측의 골스캔상 섭취계수를 비교하였다. 측정부위는 각 하지의 대퇴골간, 경골간 및 중족골로 하였다. 교감신경 절제술을 시행한 하지에서는 골스캔 소견상 수술 후 1일 또는 3일부터 동위원소 집적이 유의하게 증가되었으며 원위부로 갈수록 더욱 증가되었다. 그러나 3주 이후에는 정상측 수준으로 환원되었다. 교감신경절제술 후 골스캔상 동위원소집적이 증가되는 것은 골자체의 혈류가 증가되기 때문이며 이차적으로 골의 흡수를 유발하여 골밀도가 감소하는 것으로 생각되는데 이러한 변화는 시술 후 1일 째부터 관찰되어 사지골이 교감신경 절제에 매우 민감하게 반응하는 것을 알 수 있었다.9m}Tc$-MAA를 이용한 간 동맥 혈류 검사는 간암에서 색전술의 효과를 정확히 평가할 수 있는 유용한 검사법으로 이용될 수 있으리라 생각한다. 활성화 과정을 알아볼 수 있었으며 위상영상히스토그램을 통하여 이를 정량화하여 심실내 전기적 활성의 비동시성 여부를 추적관찰 할 수 있는 비관혈적검사임을 확인하였다.며, 3. $^{99m}Tc$으로 표지된 avidin과 streptavidin은 먼저 간으로 흡수된 후 대사된 다음 신장으로 배설된다는 사실을 알았다.damole에 의한 부작용은 흉통, 두통, 복통 등의 순이었고 전예에서 호전되었으며 생명에 위험을 초래할 수 있는 정도의 심장마비나 심부정맥은 한 예에서도 없었다. 결론적으로 dipyridamole은 약물부하 심근 SPECT 검사에 안전하게 사용할 수 있는 약물로 사료된다. 미소핵 빈도수가 증가하는 경향을 보였으나, 각 군간에 통계학적으로 유의한 차이는 없었다(p>0.05). 결론 : 임상적으로 치료를 중단하게 되는 1000mCi/60 Kg(16.67 mCi/Kg)를 투여한 군에서도 생쥐 골수내 미소핵이 발현되지 않는 것으로 보아, 방사성옥소는 비교적 안심하고 치료에 사용할 수 있는 제제로 사료되었다.반드시 비례하지만은 않아서 시간경과에 따른 추후 검사가 필요하리라 생각된다. 또한 방광요관역류가 있는 환아에서 DMSA 섭취율로 신기능을 평가할 때, 특히 영유아에서 연령에 따른 고려가 있어야 할 것으로 보인다.었다. 4) $^{99m}Tc-DISIDA$ hepatobiliary scintigram 음성율을