• The KIPS Transactions:PartC
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• v.15C no.1
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• pp.9-18
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• 2008

Prevention of attacks being made through program modification in sensor nodes is one of the important security issues. The software-based attestation technology that verifies the running code by checking whether it is modified or not in sensor nodes is being used to solve the attack problem. However, the current software-based attestation techniques are not appropriate in sensor networks because not only they are targeting static networks that member nodes does not move, but also they lacks consideration on the environment that the trusted verifier may not exist. This paper proposes a mutual attestation protocol that is suitable for sensor networks by using SWATT(Software-based ATTestation) technique. In the proposed protocol, sensor nodes periodically notify its membership to neighbor nodes and carry out mutual attestation procedure with neighbor nodes by using SWATT technique. With the proposed protocol, verification device detects the sensor nodes compromised by malicious attacks in the sensor network environments without trusted verifier and the sensor networks can be composed of only the verified nodes.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.4
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• pp.107-114
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• 2014

Things in the IoT(Internet of Things) make various services by exchanging information over networks. The IoT includes many types of WSNs(Wireless Sensor Networks) that consists of spatially distributed wireless sensor nodes and operates with the various purposes with useful technologies such as identification, sensing and communication. Typically, Zigbee network composed of low-cost and lowpower devices is mainly used for wide-area monitoring and remote device control systems. The IoT composed of various WSNs cannot interoperate among networks because of heterogeneous communication protocol and different data representation of each network, but can facilitate interconnection and information exchange among networks via the DDS, which is communication middleware standard that aims to enable real-time, high performance and interoperable data exchanges. In this paper, we proposed design of Zigbee Adaptor for two-way interoperation and data exchange between Zigbee network and other networks in the IoT. Zigbee Adaptor communicates with Zigbee network according to the Zigbee protocol and communicates with external networks via DDS. DDS-based Zigbee Adaptor can facilitate interoperation between a Zigbee network and external networks by systematic cooperation among its components.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.261-274
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• 1999

Recently, automated business processing systems, so called workflow systems, have been studied. have been studied. even though each task has noticible duration inherently, most of previous models regard it as a simple finite automation where state transitions occur instantly. In this paper, we propose a modeling method for workflow each of whose component task has minimum processing time and due-date. Firstly we provide a priority function to choose the proper alternatives when tasks fail before their due-date. The priority function considers the time-relevant factor and the semantic compatibility level to decide the best alternative. secondly, we identify six different types of execution requirements for tasks with noticible durations. They are serial, parallel, simultaneous start simultaneous termination, interleaved and nested dependency. Note that previous models deal with only serial execution and parallel execution. Lastly, we also propose graph-based methods to detect logical conflicts in time constraint-based workflow specifications.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.867-867
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• 2012

기후변화와 변동으로 인해 기온, 강수, 증발산 등의 수문순환 요소들이 과거와는 다르게 빠른 속도로 변하고 있다. 이에 따라 지난 수십 년간 기후변화가 수문학적 극한사상에 미치는 잠재적 영향은 수자원공학 관련 분야에서 관심 대상이 되어왔으며, 많은 선행 연구들은 극한 수문사상의 규모 및 빈도가 증가한다는 결과를 보여 주었다. 우리나라의 경우 최근 10년간(1999~2008년) 1일 100mm 이상 집중호우의 발생빈도는 총 385회로, 70~80년대 222회에 비해 무려 1.7배나 증가했다. 2011년의 경우 7월초부터 8월 중순까지 지속적인 장마와 집중호우로 인해 1285.3mm의 누적강수량이 발생하였으며, 서울 및 수도권 지역에서 100년 빈도 설계강수량을 초과하는 집중호우 발생으로 서울의 도심지역 곳곳이 침수되어 많은 재산피해와 인명피해를 입혔다. A1B 기후변화 시나리오에 따르면 21세기말(2071~2100년)에는 20세기말(1971~2000년)에 비해 약 17%가 증가할 것으로 전망하고 있다. 이처럼 기후변화는 특히 도시수공시설물을 설계하는데 있어 가장 중요한 변수인 극한강우사상을 변화시키기 때문에 도시배수시설물을 계획하고 설계하는 수공기술자들에게 기후변화를 고려하는 일은 자명한 일이다. 또한, 기후변화로 인한 수문과정의 점진적 변화 영향은 도시배수관련 기반시설물의 첨두홍수량과 빈도를 변화시킬 것으로 예상하고 있다. 이에 본 연구에서는 기후변동이 도시배수체계에 미치는 영향을 평가하기 위해 외부기상인자의 변동을 반영할 수 있는 비정상성 빈도해석기법을 이용하여 지속시간 1기간, 3시간, 24시간 빈도별 설계강수량을 산정한 후 도시유출모형인 XP-SWMM 모형을 통해 도시배수체계에 미치는 영향을 평가하였다. 이를 통해 현재의 도시배수체계와 비교함으로써 기후변동이 도시배수체계에 미치는 영향을 정량화하였다.

• Membrane Journal
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• v.30 no.2
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• pp.79-96
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• 2020

Secondary energy conversion systems have been briskly developed owing to environmental issue and problems of fossil fuel. They are basically operated based on electro-chemical systems. In addition, ion exchange membranes are one of the significant factors to determine performance in their systems. Therefore, the ion exchange membranes in suitable conditions must be developed to improve the performance for the electro-chemical systems. These ion exchange membranes can be classified into various types such as cation exchange membrane, anion exchange membrane and bipolar membrane. Their membranes have distinct characteristics according to the chemical, physical and morphological structure. In this review, the types of ion exchange membranes and their fabrication processes are described with main characteristics. Moreover, applications of ion exchange membranes in newly developed energy conversion systems such as reverse electrodialysis, redox flow battery and water electrolysis process are described including their roles and requirements.

• Journal of the Korea Convergence Society
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• v.10 no.11
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• pp.23-31
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• 2019

With the advent of the era of mass tourism in China and people's yearning for a better life, the demand for family tourism is increasing. This paper adds the filial piety concept variable to the original model based on the theory of planned behavior (TPB). It tests the influence mechanism of attitude, subjective norm, perceived behavior control and filial piety on the intention of family tourism behavior. The results show that； Attitude and subjective norms have significant influence on the intention of family tourism behavior; Perceptual behavior control has no significant influence on the intention of family tourism behavior; Mutual filial piety has a significant impact on family tourism behavior and authoritative filial piety has no significant effect on family tourism decision-making behavior. This conclusion expands the application boundary of the theory of planned behavior in the study of family tourism behavior intentions, and provides application reference for tourists and tourism enterprises.

• Journal of Platform Technology
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• v.9 no.2
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• pp.46-54
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• 2021

Recently, interest in the safety of Self-driving has been increasing. Self-driving have been studied and developed by many universities, research centers, car companies, and companies of other industries around the world since the middle 1980s. In this study, we propose the automatic extraction method of the threatening obstacle on the Road for the Self-driving. A threatening obstacle is defined in this study as a comparatively large object at center of the image. First of all, an input image and its decreased resolution images are segmented. Segmented areas are classified as the outer or the inner area. The outer area is adjacent to boundaries of the image and the other is not. Each area is merged with its neighbors when adjacent areas are included by a same area in the decreased resolution image. The Obstacle area and Non Obstacle area are selected from the inner area and outer area respectively. Obstacle areas are the representative areas for the obstacle and are selected by using the information about the area size and location. The Obstacle area and Non Obstacle area consist of the threatening obstacle on the road. Through experiments, we expect that the proposed method will be able to reduce accidents and casualties in Self-driving.

• Journal of the Korea Institute of Building Construction
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• v.19 no.1
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• pp.31-38
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• 2019

In this study, amine derivatives and ion exchange resins were selected to actively control penetration ions ($SO{_4}^{2-}$, $Cl^-$) as the element technology of repair materials for concrete structures in drainage environments. Ions ($SO{_4}^{2-}$, $Cl^-$) adsorption performance and corrosion resistance of calcium hydroxide solution with amine derivative and ion exchange resin were confirmed by ion chromatography and potentiostat analysis. As a result of the experiment, it was confirmed that the amine derivative is excellent in the adsorption of chlorine ion and the ion exchange resin is excellent in the adsorption of sulfate ion. It has been confirmed that corrosion resistance can be increased by proper combination of two materials in the calcium hydroxide solution containing sulfate ion and chloride ion simulating sewage environment.

• Journal of Life Science
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• v.29 no.7
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• pp.817-823
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• 2019

Immune system provides defense integrity of body against external invaders. In order to accomplish the important defending role immune system is composed of many different components which are regenerated continuously during lifespan. The key components are professional killing cells such as macrophage, neutrophil, natural killer cell, and cytotoxic T cell and professional blocking molecule, antibody, which is produced by plasma cell, the terminal differentiated B cell. Immune response is orchestrated harmoniously by all these components mediated through antigen presenting cells such as dendritic cells. Immune responses can be divided into two ways: innate immune response and adaptive immune response depending on induction mechanism. Aging is a broad spectrum of physiological changes. Likewise other physiological changes, the immune components and responses are wane as aging is progressing. Immune responses become decline and dysregulating, which is called immunosenescense. Immune components of both innate and adaptive immune response are affected as aging progresses leading to increased vulnerability to infectious diseases. Numbers of immune cells and amounts of soluble immune factors were decreased in aged animal models and human and also functional and structural alterations in immune system were reduced and declined. Cellular intrinsic changes were discovered as well. Recent researches focusing on aging have been enormously growing. Many advanced tools were developed to bisect aging process in multi-directions including immune system area. This review will provide a broad overview of aging-associated changes of key components of immunity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.807-808
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• 2016

With the recent rise in nuclear families and single-member families, there is a need for the kind of home management unaffected by neither space nor time. Moreover, electronic devices in and around the home need to be managed efficiently and prevented from overheating, and there is an increasing risk of fire, theft, and leak of personal data with these devices, which is leading to an increase in the economic costs. Accordingly, there is a growing need for an efficient and secure smart home management system. This paper proposes a home management system that uses smart devices. This system has addressed the shortcomings of a conventional Internet-based home network. Furthermore, it communicates with IoT-enabled devices and features intelligent information home appliances that are isolated from personally identifiable information and which are secure against advanced persistent threats, a type of cyber-attack.