• Journal of the Korea Convergence Society
• /
• v.9 no.12
• /
• pp.61-68
• /
• 2018

As the smartphone and mobile environment develop, the time and space constraints for individual work performance are disappearing. Companies can reduce costs and expand their business quickly through cloud computing. As the use of various cloud expands, the boundaries of users, data, and applications are disappearing. Traditional security approaches based on boundaries (Perimeter) are losing their utility in the cloud environment. This paper describes the limitations of existing network access control (NAC) in a cloud environment and suggests network security technology that complements it. The study explains the SDP and combines SDP(Software Defined Perimeter) to overcome the limitations of NAC, while at the same time explaining its role as a new framework for supporting the cloud environment. The new framework proposed in this paper suggests a software-based network security solution that supports physical and software parts, providing identity-based access control, encrypted segment management, and dynamic policy management, not IP-based.

• The Journal of the Korea Contents Association
• /
• v.21 no.6
• /
• pp.51-61
• /
• 2021

In the era of the 4th industrial revolution symbolized by the Internet of Things, big data and artificial intelligence, various embedded devices are increasing exponentially. These devices have communication functions despite their low specifications, so the possibility of personal information leakage is increasing, and security threats are also increasing. Embedded devices can have security issues at most levels, from hardware to services over the network. In addition, it is difficult to apply general security techniques because it has characteristics of resource constraints such as low specifications and low power, and the related technology has not been standardized. In this study, we present vulnerabilities and possible problems and considerations in applying SDN to embedded devices in consideration of structural characteristics and real-world discovered cases. This study presents vulnerabilities and possible problems and considerations when applying SDN to embedded devices. From a hardware perspective, we consider the problems of Wi-Fi chips and Bluetooth, the problems of open flow implementation, SDN controllers, and examples of structural properties. SDN separates the data plane and the control plane, and provides a standardized interface between the two, enabling efficient communication control. It can respond to the security limitations of existing network technologies that are difficult to respond to rapid changes.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.6
• /
• pp.897-906
• /
• 2022

In this paper, we propose a novel MAC protocol based on the harmonic transmission of ACK, called HAT-LoRa, for improving the reliability and the utilization in multiple gateway LoRa Networks. LoRa is basically vulnerable to collision due to the primitive pure ALOHA-like MAC. Whereas data frame delivery can be guaranteed by the transparent bridge of multiple receiving gateways, ACK is still transmitted by a single gateway in LoRa Network. HAT-LoRa provides the augmented reception opportunity of ACK via the simultaneous transmissions of identical ACK in multiple spreading factors. The proposed method reduces the expected transmission times of ACK double gateway environment as well as single gateway environment, by 55 and 60% in maximum, by 35% and 40% in average, in a single- and double-gateway environment, respectively. Especially, it outperforms under the environment where the distance between end device and gateways are similar to each other.

• Journal of Digital Convergence
• /
• v.19 no.11
• /
• pp.365-371
• /
• 2021

In this study, The Virtual Power Plant (VPP) solution platform considered in this study minimizes the cost and investment risk associated with the construction of power generation and transmission facilities. In addition, it includes a Demand Response (DR) program operation function to meet consumers' electricity demand. With the introduction of VPP, it is possible to provide more eco-friendly and efficient power by responding to changes in consumer load in real time through existing generators and DR programs without large-scale facility investment in power generation and transmission/distribution sectors. In order to link the communication device to the solar power and ESS linkage device, it is necessary to transmit data in the control/state between the device device and the edge system and develop an IoT device and interworking platform (OneM2M).

• Journal of Adhesion and Interface
• /
• v.23 no.4
• /
• pp.130-136
• /
• 2022

Recently, organic semiconductor based indoor photovoltaics have gained attention since they exhibit excellent photovoltaic performance than that of conventional Si-based photovoltaics. In this study, we synthesize the medium bandgap polymer of PTBT and optimize PTBT:PC₇₁BM blend films by introducing solvent additives. To this end, we select DIO and CN solvent additives and vary their contents from 0 to 3 vol%. As a result, we produce the highest power conversion efficiency of 11.31% under LED 1000 lx conditions with DIO (1.5 vol%) + CN (0.5 vol%)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.6-8
• /
• 2021

Recently, the Internet of Things technologies are continuously advanced, and IoT devices are being used in various domain. IoT platforms should not only collect and manage data by connecting to various devices, but also monitor and control them. However, conventional IoT platforms have different data types and protocols, and have the problem of not monitoring or controlling cross-platform devices. This research proposes an ontology-based IoT platform to resolve this problem. Therefore, this research analyzes the types and characteristics of conventional IoT platforms, and this paper proposes a new platform architecture based on the analysis. The proposed platform is expected to flexible data management and improvement of interoperability between other platforms by utilizing ontology technology.

• The Journal of Korean Philosophical History
• /
• no.29
• /
• pp.231-253
• /
• 2010

Xiang-xiu(向秀) tried to find compromise between naturalness(自然) and Confucian ethical code(名敎), the individual consciousness and the group consciousness in the Wei-Jin(魏晋) dynasty. He made his views on the human nature through the revealing of desire and morality of human. Xinag-xiu considered that the human nature comes from the ultimate principle of the nature(自然之理), so it's possible to provide reasonable basis to the meaning of the 'desire' and 'morality'. Furthermore, the 'desire' is regarded as the driving force of human life through the reasonable cognition, at the same time he insisted that we should control our passions by sociality and the social norm. So in the view of Xiang-xiu, the human nature has two characteristics, such as the principal of the driving force of human life and the control of the base desires and the negative desires. It could be confirmed by his opinions about the following human's nature and sticking to our last in the his Zhuangzizhu( 莊子注). Through the perspective of the human nature, Xiang-xiu emphasized the unification of the unaffected human nature and morality(sociality), the desire and the social norm.

• Journal of IKEEE
• /
• v.22 no.1
• /
• pp.93-97
• /
• 2018

In this paper, it proposes a method that uses an air pump to inject oxygen to water directly to prevent the growth of algae and cyanobacterium using MCU(Micro Controller Unit). MCU can control itself with modules of GPS, a sonic sensor, camera, conveyer belt and water pump to remove and prevent growths of algae. It can also be connected to the smart phone application software to track the system where it is and it can be controlled by the user interfaced with the smart phone application.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.709-712
• /
• 2006

다양한 종류의 컴퓨터가 사람, 사물, 환경 속에 내재되어 있고, 이들이 서로 연결되어, 필요한 곳에서 활용할 수 있는 유비쿼터스 환경에서는 홈 네트워크를 통해 이 기종 기기간 다양한 데이터 교환을 요구한다. 더욱이 원활한 영상 데이터의 처리, 전송, 모니터링 기술은 핵심적 요소가 아닐 수 없다. 공간 및 시간적인 해상도, 컬러의 표현 그리고 화질의 측정방법 등 고전적 영상 처리 연구 분야뿐만 아니라 국한된 대역폭을 갖는 홈네트워크의 전송체계에서 전송률 문제에 대한 심도 있는 연구가 필요하다. 본 논문에서는 홈네트워크 상황에서 콘텐츠의 중심이 되는 영상 데이터의 전송과 처리 그리고 제어를 위하여 새로운 움직임 추정 알고리즘을 제안한다. 각도, 거리등 다양한 환경에서 전송되어지는 스테레오 카메라의 영상데이터들은 축소, 확대, 이동, 보정 등 전처리 후 제안된 변형계층 모션벡터 추정 알고리즘을 이용하여 압축 처리, 전송된다. 기존 모션벡터 추정 알고리즘의 장점을 계승하고 단점을 보완한 변형계층 알고리즘은 비정형, 소형 매크로 블록을 이용하여 휘도의 편차가 큰 영상의 효율적 움직임 추정에 이용된다. 본 논문에서 제안한 변형계층 알고리즘과 이를 이용해 구현된 영상시스템은 유비쿼터스 환경에서 다양하게 활용될 수 있다.

• Journal of Korea Multimedia Society
• /
• v.14 no.11
• /
• pp.1500-1506
• /
• 2011

This paper is to propose for the production of a digital-based new interface for the percussion of samulnori which are drum, janggu, jing and kkwaenggwari. Newly designed interface is similar to a jing-shaped percussion, and it was designed to playall of four instruments from a single interface. Two batting sufaces, which are located both in front and at trunk of the interface, generate a hitting date creating when interface to be hit and a pressure data when to grip the handle by control unit located at the handle. The information generated is transmitted to a computer via a wireless communication, and then, the computer generate a synthesized sound based on the characteristic of each instrument.