• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1862-1872
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• 2017

To overcome the limitations of the current Central Mobility Management (CMM) protocols, IETF has been discussing about the Distributed Mobility Management (DMM) protocols that the centralized mobility functions of Home Agents (HA) are distributed to network edges closer to mobile users. The DMM protocol has some advantages of low-cost traffic delivery and high scalability. However, it faces several problems such as a high signaling cost and a complex address management. Especially, users moving at a high speed and with long-live sessions can make these problems worse. To reduce the high signaling cost for long-live sessions, we propose a novel hybrid DMM protocol allocating different mobility anchors according to the session durations. In this paper, we analyze the performance of the proposed hybrid DMM protocol and show superior performance with respect to the signaling cost.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.71-80
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• 2015

LDO(Low Drop-Out) regulators have become an essential building block in modern PMIC(Power Managment IC) to extend battery life of electronic devices. In this paper, we optimize capacitor-less LDO regulator via Geometric Programming(GP) designed using Dongbu HiTek $0.5{\mu}m$ BCDMOS process. GP-compatible models for stability and PSR of LDO regulators are derived based on monomial formulation of transistor characteristics. Average errors between simulation and the proposed model are 9.3 % and 13.1 %, for phase margin and PSR, respectively. Based on the proposed models, the capacitor-less LDO optimization can be performed by changing the PSR constraint of the design. The GP-compatible performance models developed in this work enables the design automation of capacitor-less LDO regulator for different design target specification.

• The KIPS Transactions:PartA
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• v.14A no.1 s.105
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• pp.55-62
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• 2007

Uptime of embedded processors for mobile devices are dependent on battery consumption. Especially the large portion of power consumption is known to be due to cache management in embedded processors. This paper proposes an energy efficient data cache structure for high performance embedded processors. High performance prefetching data cache issues prefetching instructions before issuing demand-fetch instructions based on reference predictions. These prefetching instruction bring reduction on memory delay by improving cache hit ratio, but on the other hand those increase energy consumption in proportion to the number of prefetching instructions. In this paper, we adopt tag history table on prefetching data cache for reducing energy consumption by minimizing parallel tag comparison. Experimental results show the proposed data cache improves performance on energy consumption as well as memory delay.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6310-6316
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• 2014

The increase in the Internet and smart device users requires high-level network security. Network security consists of Web Firewall, Network Firewall, IPS, DDoS system, UTM (Unified Treat Management), VPN, NAC (Network Access Control), Wireless security, Mobile security, and Virtualization. Most network security solutions running on IPv4, and IPv6 network services are not sufficiently ready. Therefore, in this paper, this study designed and implemented important functions of Network Access Control (NAC), which include IPv6 host detection, isolation, blocking and domain assignment for the IPv6 network. In particular, domain assignment function makes 128 bits IPv6 address management easy. This system was implemented on a KISA IPv6 test-bed using well known devices. Finally, the test result showed that all IPv6 based wired and wireless devices were well-controlled (detection, blocking, isolation and domain assignment).

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.12
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• pp.511-516
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• 2013

The cases of identification forgery and counterfeiting are increasing under the current identification system, which was established based on social conditions and administrative environments over 20 years ago. This leads to an increase of various criminal acts including illegal loan using fake ID and a number of damages caused out of good intentions that result in interference with the operations of public organizations. In addition, according to the advancement of information society, privacy protection has emerged as an important issue. However, ID card exposes individuals' personal information, such as names, resident registration numbers, photos, addresses and fingerprints, and thus the incidents associated with illegal use of personal information are increasing continuously. Accordingly, this study aimed at examining the issues of ID card forgery/counterfeiting and privacy protection and at proposing a next-generation identification system to supplement such weaknesses. The top priority has been set as prevention of forgery/counterfeiting and privacy protection in order to ensure the most important function of national identification system, which is user identification.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.5
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• pp.1117-1132
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• 2019

Recently, IT technology such as internet, mobile, and IOT has rapidly developed, making it easy to collect data necessary for business, and the collected data is analyzed as a new method of big data analysis and used appropriately for business. In this way, data collection and analysis becomes easy. In such data, personal information including an identifier such as a sensor id, a device number, IP address, or the like may be collected. However, if systematic management is not accompanied by collecting and disposing of large-scale data, violation of relevant laws such as "Personal Data Protection Act". Furthermore, data quality problems can also occur and make incorrect decisions. In this paper, we propose a new data governance maturity model(DGMM) that can identify the personal data contained in the data collected by companies, use it appropriately for the business, protect it, and secure quality. And we also propose a over all implementation process for DG Program.

• Proceedings of the Korean Society of Computer Information Conference
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• 2011.06a
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• pp.123-126
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• 2011

본 논문에서는 한국형 스마트 앱 저작도구로 미국, 일본, 한국에서 세계특허를 획득한 원더풀소프트의 M-Bizmaker를 이용하여 식품영양학과와 비서행정과 등 비전공자 회사원과 학생이 협력하는 관계에서도 중급수준의 비즈니스 앱 개발이 단기간에 가능하며 최고의 효율성을 검증할 수 있음을 확인하였다. 즉 저작도구인 M-Bizmaker를 이용하면 초중고, 대학, 일반인까지 모든 계층에서 초단기 1일 교육을 통하여 개인의 아이디어와 개성을 살린 앱을 제작할 수 있다는 결론을 도출하였다. 비전공자들이 제작한 스마트 앱의 수준은 본문에서 설명한 것 같이 단체의 일반홍보, 식단관리, 그래프를 이용한 취업현황, 구글맵 연계 주소 관리, 자동전화걸기, 사진 등의 이미지 관리, 친구 찾기와 같이 구성원을 등록하여 용이하게 관리할 수 있고, 설문조사도 쉽게 할 수 있다. 현재 세계 모바일 시장은 애플, 구글 등 미국시장이 세계시장을 선도하고 있는 상황으로 구글의 앱인벤터, 애플의 앱쿠커 등의 저작도구가 베타버젼으로 존재하지만 세계특허 수준의 한국형 저작도구인 비즈니스용 전문개발인 M-Bizmaker와는 기술수준에서 많은 격차가 존재하므로 국가적 차원에서 앱 저작도구 기술개발 인력 양성에 투자한다면 다가오는 미래에는 우리나라가 세계시장을 선도할 수 있을 것이라 사려 된다.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.125-135
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• 2010

Mobile office is becoming common as advances in mobile devices such as PDAs, Smart-phones, or wireless Internet. In this paper, we construct a mobile office environment on a geotechnical information system(GIS). Especially, web services and XML technology combined with SOA (service oriented services) are adopted for various types of mobile devices and services in a minimum cost. Web service and XML can provide an excellent SW reusability, extensibility, and interoperability even for heterogeneous distributed systems. Applications can exploit web services by just knowing server's address. Prototype system integrates a client in Visual Basic.Net and server in Java via the web services and XML data exchange. We verify effectiveness of the approach through the implementation of prototype system.

• Journal of KIISE
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• v.41 no.10
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• pp.810-823
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• 2014

The wireless mesh network based on IEEE 802.11s provides a routing based on a destination address as it inherits legacy internet architecture. However, this architecture interested in not 'what' which is originally the users goal but 'where'. Futhermore, because of the rapid increase of the number of mobile devices recently, the mobile traffic increases geometrically. It reduces the network effectiveness as increasing many packets which have same payload in the situation of many users access to the same contents. In this paper, we propose an OpenFlow-based contents routing for the wireless mesh network(WMN) to solve this problem. We implement contents layer to the legacy network layer which mesh network uses and the routing technique based on contents identifier for efficient contents routing. In addition we provide flexibility as we use OpenFlow. By using this, we implement caching technique to improve effectiveness of network as decreasing the packet which has same payload in WSN. We measure the network usage to compare the flooding technique, we measure the delay to compare environment using caching and non caching. As a result of delay measure it shows 20% of performance improve, and controller message decrease maximum 89%.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.4
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• pp.283-290
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• 2022

In this study, an IoT inspection system that can be linked with a server was developed using a gas timer and ESP-01 Wi-Fi module installed on a gas valve in the home. The server environment of the gas leak IoT inspection system was installed with APM (Apache, PHP, MySQL) to collect gas pressure data by generation so that leakage checks could be performed. In order to control the gas leak IoT inspection system, the app inventory was used to manage the gas leak check value in real time. In addition, user convenience has been enhanced so that membership management, WiFi settings, and leakage check values can be checked through mobile apps. In order to manage subscribers by region, the user list was checked by logging in in in the administrator mode so that the information on whether or not the leak test was conducted and the results could be provided. In addition, when the user presses the gas leak check button, the pressure is automatically checked, and the measured value is stored in the server, and when a gas leak occurs, the leakage check is performed after alarm and repair so that it can be used if normal. In addition, in order to prevent overlapping membership, membership management can be performed based on MAC addresses.