• Publications of The Korean Astronomical Society
• /
• v.30 no.2
• /
• pp.61-64
• /
• 2015

The brightness of Io's magnetic footprint, an indicator of electromagnetic interaction at the satellite, appears to be strongly connected to the satellite's distance from the plasma equator. As a result, the brightest footprints were detected when Io is near the interception location between the satellite's orbital plane and the plasma equator. However, volcanic activities on Io show strong correlation with the equatorward shift of Jupiter's main auroral oval, consequently causing the disappearance of Io's footprint. The same conclusion was suggested via the observation of Jupiter's hectometric radio emission, called HOM, which closely corresponds to Jupiter's auroral activity. The plasma environment near the Jovian satellites was found to vary significantly at different observational epochs. The electron density increased by approximately a factor of three from the Voyager epoch (1979) to the Galileo epoch (1995), while the electron density was found to be significantly higher (~ 5 times) in the Cassini epoch (2001). In this current study, the magnetic footprints were clearly brighter ten years ago (from peak brightness in 1998-2001) than the footprints detected in 2007. For volcanic activities on Io in 2007, there are two clear activities in February and late May. The magnetic footprint appeared to be dimmer in March 2007, expected to be the result of volcano activities in Feb 2007. However, the magnetic footprint brightness in June appeared to be slightly brighter than the footprints observed in May. The reason could be the time delay between the brightening of the sodium nebula on approximately May 31st and, a while later, the enhancement of flux tube content peaking on approximately June 5th. On the other hand, Io's magnetic footprints were observed during June 1st - 10th when they may not yet have been affected by the increase in mass outflow due to the increase of plasma density.

• Journal of Korea Multimedia Society
• /
• v.20 no.12
• /
• pp.1928-1939
• /
• 2017

Fog computing is another paradigm of the cloud computing, which extends the ubiquitous services to applications on many connected devices in the IoT (Internet of Things). In general, if we access a lot of IoT devices with existing cloud, we waste a huge amount of bandwidth and work efficiency becomes low. So we apply the paradigm called fog between IoT devices and cloud. The network architecture based on cloud and fog computing discloses the security and privacy issues according to mixed paradigm. There are so many security issues in many aspects. Moreover many IoT devices are connected at fog and they generate much data, therefore light and efficient security mechanism is needed. For example, with inappropriate encryption or authentication algorithm, it causes a huge bandwidth loss. In this paper, we consider issues related with data encryption and authentication mechanism in the network architecture for cloud and fog-based M2M (Machine to Machine) IoT services. This includes trusted encryption and authentication algorithm, and key generation method. The contribution of this paper is to provide efficient security mechanisms for the proposed service architecture. We implemented the envisaged conceptual security check mechanisms and verified their performance.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.11a
• /
• pp.128-130
• /
• 2017

본 논문에서는 IoST(Internet of Small Things)로 분류되는 소형화된 사물에 적합하도록 기존 2핀을 사용하여 통신하는 I2C 직렬 통신과 달리 단일 핀을 사용하여 온도 습도 통신이 가능한 통신 기술을 연구하였다. 기존의 센서 정보를 주고받는 I2C 직렬 통신 방식은 클럭과 데이터 핀을 사용하여 비교적 빠른 속도로 데이터 전송을 하지만 단일 핀 사용 방식보다 전력소모에 큰 영향을 주기 때문에 IoST 통신에서 보다 적합하도록 하드웨어 설계를 단순화하여 면적을 줄이고 전력 소모를 줄이도록 하는 방안을 연구하였다.

• The Journal of Bigdata
• /
• v.6 no.1
• /
• pp.161-178
• /
• 2021

The importance of 'Big Data' is increasing to the point that it is likened to '21st century crude oil'. For smart city IoT data, attention should be paid to quality control as the quality of data is associated with the quality of public services. However, data quality indicators presented through ISO/IEC organizations and domestic/foreign organizations are limited to the 'User' perspective. To complement these limitations, the study derives supplier-centric indicators and their priorities. After deriving 3 categories and 13 indicators of supplier-oriented smart city IoT data quality evaluation indicators, we derived the priority of indicator categories and data quality indicators through AHP analysis and investigated the feasibility of each indicator. The study can contribute to improving sensor data quality by presenting the basic requirements that data should have to individuals or companies performing the task. Furthermore, data quality control can be performed based on indicator priorities to provide improvements in quality control task efficiency.

• International journal of advanced smart convergence
• /
• v.11 no.3
• /
• pp.36-41
• /
• 2022

In the 21st century, information collection and information provision based on digital informatization and intelligent automation are emerging as one of the social problems in the society for the elderly and the vulnerable groups in the welfare society including the disabled, and various methods are being studied to find realistic alternatives. Among these factors, the problem of the elderly living alone is emerging as the most serious, and as a realistic approach to solve some problems by applying information devices, it is a monitoring system using the Internet of Things(IoT). The need for an optimized system is emerging. In this study, the state of the elderly and the elderly living alone can be measured remotely by applying IoT technology. We present the research cases of a Breathing Sensor-based Smart Monitoring System that is used as a smart information system and used as a monitoring system for the elderly and infirm when it is identified as deceased through state detection

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.8
• /
• pp.311-317
• /
• 2016

Many services have been developed that are based on smart devices, and security between devices is emphasized. A beacon on the current IoT(Internet of Things) services has been utilized in the commercial field and is being applied to the services of the home IoT. On the other hand, the beacon is weak to security using Bluetooth-based services. Therefore, it is important to strengthen the security of the beacon. This paper proposes a dual security technique that can enhance the security of beacon-based services. The dual security architecture and security process is proposed based on beacon and authentication service. In addition, mobile application was developed and validated based on the beacon for proving the suitability of the proposed technique. The experimental method for verification are the authentication failure case, such as 1st authentication fail, and authentication success case, such as 1st authentication success and 2nd authentication success. The components of the verification experiments consists of two beacons (matched with Beacon ID, mismatched with Beacon ID), one mobile device and authentication application. This was tested to verify the compatibility of the dual security architecture and 1st/2nd authentication process.

• Smart Media Journal
• /
• v.5 no.3
• /
• pp.17-24
• /
• 2016

Korean agriculture is currently experiencing difficulties as a cause of rural depopulation, aging of rural population, grain self-sufficiency rate decline, and deepening of climate change. It is necessary to ensure our country's agriculture industrial competitiveness in accordance with opening of FTA imports expanded. To ensure the underdeveloped competitive, Korean government defines the 3rd generation model from 1st generation model to extend the smart farms of Korean types. The agriculture smarting overcomes the growth limitations of agriculture, and efforts to develop 6th + ${\alpha}$ industry. In this paper, We define and verify the IoF(Internet of Farming)-Cloud based substantial services about 2rd generation model, and propose a greenhouse of IoF-Cloud testbed.

• Journal of the Korean Society of Systems Engineering
• /
• v.11 no.2
• /
• pp.85-93
• /
• 2015

Warehouse Management System (WMS) is a key control for Material Handling System (MHS) and Inventory Control System (ICS). How to design and implement for WMS is crucial factor for achieving the key performance index for Manufacturing Industry. In particular, iron and steel making industry, where the volume and weight is large and hence FIFO (First Input First Out) is not working, how to design WMS is a key factor. In this paper, we systematically define the problem of WMS via developing StR (Stakeholders' Requirements) or ORD (Operational Requirement Documents), SyR (System Requirement), and SA (System Architecture) based on the emerging technologies. In particular, IoT (Internet of Things), CPS (Cyber Physical System) concepts and enabling technologies haves been incorporated in developing Smart WMS. The deliverables of the research can provide a conceptual framework for developing the next generation industrial WMS.

• Physical Therapy Rehabilitation Science
• /
• v.10 no.2
• /
• pp.167-174
• /
• 2021

Objective: Single leg bridge exercise (SLBE) improves trunk muscle activation and provides muscle stability by aligning joints related to posture. This preliminary study aimed to investigate the effects of SLBE on abdominal muscle activation in subacute stroke patients. Design: Cross-sectional study. Methods: Fifteen subacute stroke patients (9 males, 6 females) voluntarily participated in this study. SLBE was performed on the affected side. Each individual patient performed an SLBE ten times in three sets and was asked to hold their position for 5 s. Muscles activity was recorded using a surface electromyography (EMG) system before and after the SLBE. A surface EMG system was used to analyze the muscle activity during general bridge exercise, including the rectus abdominis (RA), internal oblique (IO), and external oblique (EO) abdominal muscles. Results: Muscle activity of both EO and IO on the affected side significantly increased (p<0.05), whereas the muscle activity of the RA and the three muscles on the unaffected side did not show a significant difference. In addition, improvement in muscle asymmetry of the EO and IO showed a significant change after SLBE (p<0.05). Conclusions: SLBE is effective in activating the abdominal muscles of stroke patients on the affected side and is a helpful exercise intervention that activates the muscles to transform asymmetric abdominal muscles into symmetric patterns.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.2 s.48
• /
• pp.11-19
• /
• 2006

In this paper the seismic performances of 4, 10, and 30-story staggered truss systems (STS) were evaluated by observing the force-displacement relationship up io failure. The results were compared with the seismic performance of conventional moment resisting frames and braced frames. According to the analysis results, the STS showed relatively satisfactory lateral load resisting capability. However, in the mid- to high-rise STS, plastic hinges formed first at the chords were transferred to vertical members of the vierendeel panels, which formed a week link and subsequently leaded to brittle collapse of the structure. Therefore to enhance the ductility of STS it would be necessary to reinforce the vertical bracing members of the virendeel panels so that the plastic hinges, once toned in cord members of a virendeel panel, spread out to virendeel panels of neighboring stories.