• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.4
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• pp.753-758
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• 2009

Recently the high-end CMOS image sensors are developed, conforming to the SMIA CCP2 specification, which is a high-speed low-power serial interface based on LVDS technology. But this kind of technology trend makes the existing equipments are no longer useful, although their capability is still good enough to handle the recent image sensors if there was no interfacing problem. In this paper, we propose and realize a data protocol conversion system that translates the SMIA CCP2 serial signals into the existing 10-bit parallel signals. The proposed system is composed of a de-serializer and a FPCA chip, and thus can be constructed on a small PCB which enables easy integration between the existing equipments and the new high-end image sensors. Besides, the maximum transfer rate by the SMIA specification is also achieved on the implemented system. So it is expected that the implemented system can be used as a general-purpose protocol converter in a variety of sensor-related application fields.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2568-2574
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• 2005

Control architecture of the action based robot engineering can be divided into two types of deliberate type - and reactive type- controller. Typical deliberate type, slow in reaction speed, is well suited for the realization of the higher intelligence with its capability to forecast on the basis of environmental model according to time flow, while reactive type is suitable for the lower intelligence as it fits to the realization of speedy reactive action by inputting the sensor without a complete environmental model. Looking at the environments in the application areas in which robots are actually used, we can see that they have been mostly covered by the uncertain and unknown dynamic changes depending on time and place, the previously known knowledge being existed though. It may cause, therefore, any deterioration of the robot performance as well as further happen such cases as the robots can not carry out their desired performances, when any one of these two types is solely engaged. Accordingly this paper aims at suggesting Goal-oriented Geometric Model(GGM) Based Intelligent System Architecture which leads the actions of the robots to perform their jobs under variously changing environment and applying the suggested system structure to the navigation issues of the robots. When the robots do perform navigation in human life changing in a various manner with time, they can appropriately respond to the changing environment by doing the action with the recognition of the state. Extending this concept to cover the highest hierarchy without sticking only to the actions of the robots can lead us to apply to the algorithm to perform various small jobs required for the carrying-out of a large main job.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.407-422
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• 2014

Objective: The purpose of the study is to develop quantitative usability evaluation criteria for senior-friendly autonomous transportation robot. Background: The Republic of Korea has become the most rapidly aging society, and is anticipated to enter the post-aged society in 2026. To raise the quality of life of a senior with limited mobility and to reduce the burden of caregivers, many high-tech assistive products with information technologies are developed nowadays. The senior-friendly autonomous transportation robot is one person robot vehicle to move a senior to the destination for hospitals, nursing homes or silver town complex. With built-in navigation system and environmental monitoring censors, it automatically seeks the path to the destination and avoids collision to obstacles and pedestrians on the way. Due to the early stage of the product, few usability studies in this field have been done, mostly on general service robots to assist seniors, power wheelchairs and delivery robots. ISO and KS standards for the service robots are focused on safety. Method: Based on the reference usability index, the early draft of the usability evaluation questionnaires was developed. After small group tests and interviews, the experts modified the initial draft to the Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot (UEC-SFATR). Result: UEC-SFATR consisted of 4 subscales - Safety, Controllability, Efficiency and Satisfaction. All of the 4 subscales of UEC-SFATR were passed the reliability criteria by 4 groups of seniors, divided by gender and familiarity of smart-devices. Conclusion: UEC-SFATR covers wider area of user experiences of the SFATR and is a good measurement tool to help both the users and developers of the robot. Application: This study provides guide to the future product development and product competitiveness evaluation by quantifying user experiences for the SFATR.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.31-34
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• 2016

System In Package (SiP) is getting popular and momentum for the recent wearable, IoT and connectivity application apart from mobile phone. This is driven by market demands of cost competitive, lighter and smaller/thinner and higher performance. As one of many semiconducting assembly products, Leadframe product has been widely used for low cost solution, light/ small and thin form factor. But It has not been applied for SiP although Leadframe product has many advantages in cost, size and reliability performance. SiP is mostly based on laminate substrate and technically difficult on Leadframe substrate because of a limitation in SMT performance. In this paper, Leadframe based SiP product has been evaluated about key technical challenges in SMT performance and electrical shield technology. Mostly Leadframe is considered not available to apply EMI shield because of tie-bar around package edge. In order to overcome two major challenges, connection bars were deployed properly for SMT pad to pad and additional back-side etching was implemented after molding process to achieve electrical isolation from outer shield coating. This product was confirmed assembly workability as well as reliability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5537-5555
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• 2017

Having the characteristics of unlinkability, anonymity, and unforgeability, blind signatures are widely used for privacy-related applications such as electronic cash, electronic voting and electronic auction systems where to maintain the anonymity of the participants. Among these applications, the blinded message is needed for a certain purpose by which users delegate signing operation and communicate with each other in a trusted manner. This application leads to the need of proxy blind signature schemes. Proxy blind signature is an important type of cryptographic primitive to realize the properties of both blind signature and proxy signature. Over the past years, many proxy blind signature algorithms have been adopted to fulfill such task based on the discrete logarithm problem (DLP) and the elliptic curve discrete log problem (ECDLP), and most of the existing studies mainly aim to provide effective models to satisfy the security requirements concerning a single blinded message. Unlike many previous works, the proposed scheme applies the signcryption paradigm to the proxy blind signature technology for handling multiple blinded messages at a time based on elliptic curve cryptography (ECC). This innovative method thus has a higher level of security to achieve the security goals of both blind signature and proxy signature. Moreover, the evaluation results show that this proposed protocol is more efficient, consuming low communication overhead while increasing the volume of digital messages compared to the performance from other solutions. Due to these features, this design is able to be implemented in small low-power intelligent devices and very suitable and easily adoptable for e-system applications in pervasive mobile computing environment.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.50-56
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• 2015

An efficient fast response hysteretic buck converter suitable for mobile application is propoesed. The problems of large output ripple and difficulty in using of small power inductor that conventional hysteretic converter has are improved by adding ramp generator. and the changeable switching frequency with load current is fixed by adding a delay time control circuit composed of PLL structure resulting in decrease of EMI noise. The circuits are implemented by using BCDMOS 0.35um 2-polt 4-metal process. Measurement results show that the converter operates with a switching frequency of 1.85MHz when drives 80mA load current. As the converter drives over 170mA load current, the switching frequency is fixed on 2MHz. The converter has output ripple voltage of less 20mV and more than efficiency 85% with 50~500mA laod current condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2097-2104
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• 2009

In terrestrial communications, high data rate transmission can be achieved by splitting the coverage area into small cells through base stations and reusing the resource efficiently. However, the geographical features of maritime communications require the long transmission range, and it is not practical to install base station on the sea to set up the similar deployment as the terrestrial communications, so MF/HF band modem with low data rate are currently utilized for maritime communications. And the expensive satellite communication via Inmarsat is the conventional solution for the high data rate transmission on the sea. To reduce the cost, Ad-hoc network is proposed to apply on the sea, which requires no base station for the peer-to-peer communications. In this paper, we denominate this maritime environment specific Ad-hoc network as Nautical Ad-hoc Network (NANET). Furthermore, the deployment scenario for the NANET, and the analysis on multiple access and duplexing schemes for the NANET are discussed in this paper, which serves as the cornerstone for the further NANET research and development.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.4
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• pp.9-16
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• 2020

Pronunciation recognition systems that use only video information and ignore voice information can be applied to various customized services. In this paper, we develop a system that applies a Bayesian classifier to distinguish Korean vowels via lip shapes in images. We extract feature vectors from the lip shapes of facial images and apply them to the designed machine learning model. Our experiments show that the system's recognition rate is 94% for the pronunciation of 'A', and the system's average recognition rate is approximately 84%, which is higher than that of the CNN tested for comparison. Our results show that our Bayesian classification method with feature values from lip region landmarks is efficient on a small training set. Therefore, it can be used for application development on limited hardware such as mobile devices.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.5
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• pp.333-338
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• 2019

In this study, we introduce a dual-band ground radiation antenna using an endless metal-rim mode control method that operates in the WLAN band. In the proposed antenna, the metal-rim modes are excited as one- and two-wavelength-mode radiators by a dual-band ground radiation antenna, which occupies a small space on the ground plane. The metal rim surrounds the ground plane with a gap of only 2 mm. In addition, two capacitors are inserted between the ground plane and the endless metal rim to control the one- and two-wavelength modes of the endless metal rim. Based on simulation and measurement results, we noted that the proposed antenna has an impressively high radiation performance.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.107-115
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• 2019

Effective construction safety management systems are desperately required for reducing damage caused by increasing safety accidents in construction sites. Safety accidents in construction sites can effectively protect if proactive measures are taken to prevent unauthorized worker access the expected hazardous area. In this study, we have developed a IoT(Internet of Things)-based dangerous zone alarming system for safety management in construction sites, which can be operated at low cost in large-scale sites as well as small and medium-sized construction sites. The development system utilizes a Zigbee-based beacon technology and cellular mobile communication technology to detect when authorized workers, unauthorized field workers or outsiders approaches hazardous zones. If somebody approaches the dangerous zones the system notifies immediately to the safety manager with a danger warning signal. It is expected that this system can effectively prevent safety accidents when applied to construction sites.